Stockholders' Equity (Tables)

3 Months Ended

Apr. 02, 2021

Stockholders Equity Note [Abstract]

Schedule of Compensation Cost

The cost that has been charged against income for stock-based compensation is set forth below (in thousands):

	Three Months Ended
	April 2, 2021		April 3, 2020
Employee stock options	$	2,472	$	2,232
Restricted stock		166		78
Restricted stock units		537		549
Performance stock units		93		—
Nonemployee stock options		62		62
Total stock-based compensation expense	$	3,330	$	2,921

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

The Company recorded stock-based compensation costs in the following categories (in thousands):

	Three Months Ended
	April 2, 2021		April 3, 2020
Cost of sales	$	35	$	22
General and administrative		1,439		1,085
Marketing and selling		833		1,055
Research and development		1,023		759
Total stock-based compensation expense, net		3,330		2,921
Amounts capitalized as part of inventory		309		269
Total stock-based compensation expense, gross	$	3,639	$	3,190

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The risk-free rate is based on the U.S. Treasury yield curve corresponding to the expected term at the time of the grant.

	Three Months Ended
	April 2, 2021			April 3, 2020
Expected dividend yield		0	%		0	%
Expected volatility		53	%		53	%
Risk-free interest rate		0.84	%		0.54	%
Expected term (in years)		5.38			5.72

Schedule of Share-based Compensation, Stock Options, Activity

A summary of stock option activity under the Plan for the three months ended April 2, 2021 is presented below:

	Stock Options (in 000’s)			Minimum Exercise Price		Maximum Exercise Price
Outstanding at January 1, 2021		3,418
Granted		243
Exercised		(376	)
Forfeited or expired		—
Outstanding at April 2, 2021		3,285		$	5.34	$	106.51
Exercisable at April 2, 2021		2,324

Schedule of Share-based Compensation, Restricted Stock, Restricted Stock Units and Performance Stock Units Activity

A summary of restricted stock, RSUs and PSUs activity under the Plan for the three months ended April 2, 2021 is presented below:

	Restricted Stock (in 000’s)		Restricted Stock Units (in 000’s)			Performance Stock Units (in 000’s)
Unvested at January 1, 2021		11		122			15
Granted		—		48			—
Vested		—		(33	)		—
Forfeited or expired		—		—			—
Unvested at April 2, 2021		11		137			15