The Company’s stock-based compensation is in accordance with the amended 2015 Incentive Compensation Plan (the “Plan”), pursuant to which the Compensation Committee of the Company is authorized to grant up to 7,150,000 shares to officers and employees of the Company, in the form of equity-based awards, including time or performance based options and restricted stock. In addition, the Company may grant cash-settled awards, including stock-appreciation rights (SARs) and phantom stock awards. As of December 31, 2020, there were 2,275,197 shares available for grant under the Plan.

In June 2019, the Company's shareholders approved the 2019 Employee Stock Purchase Plan (the "ESPP"), which was effective July 1, 2019. 500,000 shares of common stock are reserved for issuance under the ESPP. The ESPP allows eligible employees to purchase shares of common stock at a discount of up to 15% through payroll deductions of their eligible compensation, subject to any plan limitations. The ESPP provides for six-month offering periods beginning January 1 and July 1 of each year, and each offering period consists of a six-month purchase period. On each purchase date, eligible employees may purchase the Company's common stock at a price per share equal to 85% of the lesser of (1) the fair market value of the common stock on the offering date or (2) the fair market value of the common stock on the purchase date. As of December 31, 2020, 314,117 shares had been issued under the ESPP.

Total stock-based compensation recorded by the Company for the year ended December 31, 2020, 2019 and 2018 for both equity and liability-classified awards was $3.6 million, $2.7 million and $2.9 million respectively.


(in thousands)	Year Ended Year Ended December 31, 2020		Year Ended Year Ended December 31, 2019		Year Ended Year Ended December 31, 2018
Cost of sales	$	95	$	142	$	191
Selling, general and administrative expenses	3,192		2,384		2,413
Research and development expenses	311		188		293
Total	$	3,598	$	2,714	$	2,897

During the year ended December 31, 2019, the Company’s compensation committee approved time-based stock options ("Options") to be granted to officers and employees of the Company, which vest ratably over three years. No Options were granted during the year ended December 31, 2020. A summary of the status of the Company’s Options for the years ended December 31, 2020 and 2019 were as follows:


	Number of Share Underlying Awards	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (years)
Outstanding at January 1, 2019	982,324	$	9.38	7.18
Granted	324,450	3.34		9.25
Exercised	—	—		0
Forfeited or expired	(498,954)	10.17		6.27
Outstanding at December 31, 2019	807,820	6.44		7.69
Exercisable at December 31, 2019	403,831	8.66		6.48
Vested and expected to vest at December 31, 2019	807,820	$	6.44	7.69

Outstanding at January 1, 2020	807,820	$	6.44	7.69
Granted	—	—		0
Exercised	—	—		0
Forfeited or expired	(8,250)	3.34		9.43
Outstanding at December 31, 2020	799,570	6.47		6.67
Exercisable at December 31, 2020	572,858	7.43		6.11
Vested and expected to vest at December 31, 2020	799,570	$	6.47	6.67

The fair value of each Option was estimated on the date of grant using the Hull-White or Black-Scholes option pricing models with the assumptions described below. For the periods indicated, since the Company has limited historical volatility information available, the expected volatility was based on actual volatility for comparable public companies projected over the expected terms of Options and the actual volatility for the Company since the Business Combination. The Company records forfeitures as they occur. The risk-free interest rate was based on the U.S. Treasury yield curve at the time of the grant over the expected term of the Options. The expected life for the Hull-White model was calculated as the average time to achieve the 2.0x strike exercise price in the simulation. The expected life for the Black-Scholes model was estimated using the simplified method.


						Year Ended December 31, 2019
Weighted average grant date fair value						$1.72
Risk-free interest rate						2.27%
Expected life (years)						6.00
Estimated volatility factor						52.33%
Expected dividends						None

During the year ended December 31, 2019, the Company’s compensation committee approved time-based stock appreciation rights ("SARs") to be granted to employees of the Company outside of the United States, which vest ratably over three years. No SARs were granted during the year ended December 31, 2020. A summary of the Company’s SARs as of December 31, 2020 and 2019 were as follows:


	Number of Awards	Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (years)
Outstanding at January 1, 2019	105,925	$	9.12	6.75
Granted	5,450	3.34		9.25
Exercised	—	—		0.00
Forfeited or expired	(27,500)	12.00		5.67
Outstanding at December 31, 2019	83,875	8.90		6.00
Exercisable at December 31, 2019	76,558	9.42		5.72
Vested and expected to vest at December 31, 2019	83,875	$	8.90	6.00

Outstanding at January 1, 2020	83,875	$	8.90	6.00
Granted	—	—		0.00
Exercised	—	—		0.00
Forfeited or expired	(35,750)	10.32		5.42
Outstanding at December 31, 2020	48,125	12.00		4.69
Exercisable at December 31, 2020	48,125	12.00		4.69
Vested and expected to vest at December 31, 2020	48,125	$	12.00	4.69

Holders of these SARs are entitled under the terms of the Plan to receive cash payments calculated based on the excess of the Company’s stock price over the target price in their award; consequently, these awards are accounted for as liability-type awards, and the Company measures compensation cost based on their estimated fair value at each reporting date and the number of options expected to vest.

Upon issuance, the fair value of each SAR award was estimated using the Hull-White option pricing model with the assumptions described below. For the periods indicated, since the Company has limited historical volatility information available, the expected volatility was based on actual volatility for comparable public companies projected over the expected terms of SAR awards. The Company records forfeitures as they occur. The risk-free interest rate was based on the U.S. Treasury yield curve at the time of the grant over the expected term of the SAR awards. The expected life was calculated as the average time to achieve the 2.0x strike exercise price in the simulation. SARs are liability classified within Accrued expenses and other current liabilities and they are revalued at each reporting date. The assumptions used to value the SARs as of their issuance dates and as of December 31, 2020 and 2019 are presented below:


	At issuance				As of December 31, 2020		As of December 31, 2019
Fair value of awards	$1.86				$0.03		$0.17
Risk-free interest rate	1.74	-	2.98	%	0.14	%	1.61	%	-	1.71	%
Expected life (years)	5.83	-	6.50		2.33		2.84		-	5.22
Estimated volatility factor	47.52	-	48.00	%	54.50	%	52.33	%	-	54.50	%
Expected dividends	None				None		None

During the year ended December 31, 2020 and December 31, 2019, the Company’s compensation committee approved equity-classified performance-based restricted stock units (RSUs) and time based restricted stock to be granted to officers and employees of the Company, which vest ratably over three years. A summary of the Company’s restricted stock awards as of December 31, 2020 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
Non-vested Restricted Stock & RSUs at January 1, 2019	668,696	$	6.76
Granted	853,650	3.13
Vested	(267,249)	5.48
Forfeited or expired	(239,275)	4.47
Non-vested Restricted Stock & RSUs at December 31, 2019	1,015,822	$	4.26

Non-vested Restricted Stock & RSUs at January 1, 2020	1,015,822	$	4.26
Granted	1,906,745	1.65
Vested	(232,136)	5.21
Forfeited or expired	(236,809)	4.44
Non-vested Restricted Stock and RSUs at December 31, 2020	2,453,622	$	2.12

Unrecognized compensation expense for performance-based restricted stock and time-based restricted stock is $4.1 million, which is expected to be recognized over a weighted average period of 1.9 years.

During the year ended December 31, 2019, the Company’s compensation committee approved phantom stock awards to be awarded to employees of the Company located outside of the United States, which vest ratably over three years. These awards will be settled in cash upon vesting and are therefore liability-classified within Accrued expenses and other current liabilities, requiring re-measurement at each balance sheet date. A summary of the Company’s Phantom Stock Awards as of December 31, 2020 is as follows:


	Number of Awards	Weighted-Average Grant Date Fair Value
Non-vested phantom stock awards at January 1, 2019	112,183	$	6.71
Granted	136,450	3.09
Vested	(43,219)	5.41
Forfeited or expired	(22,532)	4.51
Non-vested phantom stock awards at December 31, 2019	182,882	$	4.30

Non-vested phantom stock awards at January 1, 2020	182,882	$	4.30
Granted	247,166	1.65
Vested	(57,986)	4.49
Forfeited or expired	(46,420)	2.42
Non-vested phantom stock awards at December 31, 2020	325,642	$	2.26

On January 31, 2014, 20,125 founder shares were transferred to each of three independent directors (“Director Shares”) of the Company, adjusted for the effect of stock dividends in February 2014 (for a total of 60,375 founder shares). On March 13, 2014, the underwriters exercised a portion of the over-allotment option from the Public Offering, resulting in a portion of the Director Shares being forfeited. As a result, the Director Shares were adjusted ratably resulting in each director holding 18,375 Director Shares (for a total of 55,125 Director Shares) at December 31, 2020.

The Director Shares were effectively subject to achievement of two performance conditions — the Company completing its initial public offering (IPO) and a business combination within 21 months of the IPO. Additionally, 25% (13,781 shares in the

aggregate) were subject to forfeiture if the Company’s stock price does not trade at or above $13 for any 20 trading days within a 30 day period commencing on the Closing Date through July 31, 2020. 13,781 shares were forfeited on July 31, 2020.

The grant date fair value of the Director Shares with performance conditions was estimated as of their deemed grant date of January 31, 2014. The aggregate fair value of the Director Shares of $0.4 million was recognized as an expense upon consummation of the Business Combination, at which point the performance conditions had been achieved.

Certain directors receive shares of restricted stock subject to the terms, provisions and restrictions of the 2015 Incentive Compensation Plan. The shares granted during the year ended December 31, 2020 and 2019, vest over a one year period on the one year anniversary of each holder's grant date, provided the Director is still serving as a director of the Company. Upon termination of directorship for any reason, the Director immediately forfeits any unvested shares without payment. A summary of the Company’s time-based restricted stock awarded to the Board of Directors for the year ended December 31, 2020 is as follows:


	Number of Shares	Weighted-Average Grant Date Fair Value
Non-vested time-based restricted stock at January 1, 2019	64,369	$	7.21
Granted	233,362	2.29
Vested	(90,308)	5.80
Forfeited or expired	—	—
Non-vested time-based restricted stock at December 31, 2019	207,423	$	2.29

Non-vested time-based restricted stock at January 1, 2020	207,423	$	2.29
Granted	214,177	2.45
Vested	(234,298)	2.28
Forfeited or expired	—	—
Non-vested time-based restricted stock at December 31, 2020	187,302	$	2.48