STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 27, 2016

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

Summary of Valuation Assumptions

The Black-Scholes model requires the input of highly subjective assumptions, which are summarized in the table below for the three months ended March 27, 2016 and March 29, 2015 (assumptions are not applicable for the three months ended March 27, 2016 as there were no stock options granted during that period):

	Three Months Ended
	March 27, 2016	March 29, 2015
Expected dividend yield	N/A	—
Expected stock price volatility	N/A	66%
Risk-free interest rate	N/A	1.1%
Expected life of options in years	N/A	4.0

Schedule of Stock-Based Compensation

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

	Three Months Ended
	March 27, 2016		March 29, 2015
Stock-based compensation by type of award:
Stock options	$	199	$	245
Restricted stock units	313		266
Employee stock purchase plan	7		5
	$	519	$	516
Stock-based compensation by category of expense:
Cost of goods sold	$	46	$	34
Research, development and engineering	42		63
Selling, general and administrative	431		419
	$	519	$	516