The Company (Tables)

12 Months Ended

Dec. 31, 2020

The activity in the warranty accrual during the years ended December 31, 2020, and 2019, is summarized as follows:

	December 31,
	2020			2019

Accrual at beginning of year	$	232		$	238
Additions charged to warranty expense		67			222
Expiring warranties/claims satisfied		(186	)		(228	)
Total		113			232
Less: current portion		(87	)		(170	)
Total long-term accrued warranty costs	$	26		$	62

Calculation of Basic and Diluted Loss Per Share by Class of Security

The following table presents the calculation of basic and diluted loss per share by each class of security for the years ended December 31, 2020, and 2019:

	Year ended						Year ended
	December 31, 2020						December 31, 2019
	Common Stock			Series C Convertible Preferred Stock			Common Stock			Series C Convertible Preferred Stock

Loss attributable to each class	$	(4,394	)	$	(18	)	$	(3,597	)	$	(193	)

Weighted average number of shares outstanding during the period		33,609,922			368			31,978,665			4,577

Basic and Diluted loss per share	$	(0.13	)	$	(48.59	)	$	(0.11	)	$	(42.24	)

Antidilutive Securities Excluded from Computation of Earnings Per Share

The following common stock equivalents outstanding during the years ended December 31, 2020, and 2019, have been excluded from the loss per share calculation as their inclusion would have been anti-dilutive:

	Year Ended December 31,
		2020	2019
Common stock purchase warrants		434,791	1,517,528
Restricted stock units		131,247	128,417
Common stock options		4,957,288	4,235,451
Total		5,523,326	5,881,396