STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 27, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

The Black-Scholes model requires the input of highly subjective assumptions, which are summarized in the table below for the three and nine months ended September 27, 2015 and September 28, 2014 (assumptions are not applicable for the three months ended September 27, 2015 as there were no stock options granted during that period):



	Three Months Ended		Nine Months Ended
	September 27, 2015	September 28, 2014	September 27, 2015	September 28, 2014
Expected dividend yield	N/A	—	—	—
Expected stock price volatility	N/A	65%	66%	67%
Risk-free interest rate	N/A	1.4%	1.1%	1.3%
Expected life of options in years	N/A	4.0	4.0	4.0

Schedule of Stock-Based Compensation

Our stock-based compensation for the periods indicated was as follows (in thousands):



	Three Months Ended				Nine Months Ended
	September 27, 2015		September 28, 2014		September 27, 2015		September 28, 2014
Stock-based compensation by type of award:
Stock options	$	254	$	244	$	765	$	740
Restricted stock units	317		143		890		309
Employee stock purchase plan	5		12		15		36
	$	576	$	399	$	1,670	$	1,085
Stock-based compensation by category of expense:
Cost of goods sold	$	36	$	12	$	109	$	23
Research, development and engineering	60		47		193		135
Selling, general and administrative	480		340		1,368		927
	$	576	$	399	$	1,670	$	1,085