8. Income Taxes (Details 2) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Operating loss carryforwards	$ 2,263	$ 2,787
R&D tax credit	1,195	1,021
AMT tax credit	303	269
Section 263A costs	552	421
R&D costs	861	1,428
Amortization	33	0
Asset reserves:
Bad debts	18	18
Inventory reserve	601	608
Accrued expenses:
Non-qualified stock options	78	78
Compensation	240	202
Warranty	368	315
Deferred tax assets	6,512	7,147
Less APIC pool allowance	(380)	(380)
Total deferred tax assets	6,132	6,767
Deferred tax liabilities:
Depreciation	(426)	(370)
Amortization	0	(364)
Unrealized gain	(245)	0
Total deferred tax liabilities	(671)	(734)
Net deferred tax assets	$ 5,461	$ 6,033