The following table summarizes the allocation of stock-based compensation in the accompanying consolidated statements of income:



	For the three months ended				For the six months ended
	June 28, 2019		June 29, 2018		June 28, 2019		June 29, 2018
Cost of sales	$	114	$	131	$	243	$	233
Sales and marketing	113		139		239		299
Research and development	155		154		320		296
General and administrative	1,239		1,361		2,548		3,003
Total	$	1,621	$	1,785	$	3,350	$	3,831

The following table summarizes the activity for the Company's unvested restricted stock units ("RSU") for the six months ended June 28, 2019.



	Unvested RSUs
	Number of shares outstanding		Weighted-average grant date fair value
Unvested at December 28, 2018	655		$	29.34
Granted	19		$	71.94
Canceled	(9	)	$	30.97
Vested	(169	)	$	26.45
Unvested at June 28, 2019	496		$	31.91

As of June 28, 2019, the Company had approximately $11,208 of unrecognized stock-based compensation expense related to RSUs, which will be recognized over the remaining weighted-average vesting period of approximately 2.46 years.

During the six months ended June 28, 2019, 190 shares of common stock were issued due to the exercise of stock options, resulting in proceeds of $966. No options to purchase common stock expired or were forfeited during the six months ended June 28, 2019. As of June 28, 2019, stock-based compensation expense related to stock options has been fully recognized.