CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (125)	$ (1,646)
Adjustments to reconcile net loss to net cash used in operating activities:
Allowance for doubtful accounts and other	(9)	28
Provision for excess and obsolete inventories	89	678
Non-cash lease expense	172
Depreciation and amortization	365	329
Stock-based compensation	651	542
Amortization of discount on investments	(8)	(2)
Changes in assets and liabilities:
Accounts receivable	(27)	(1,596)
Inventory	133	(272)
Prepaid expenses and other assets	(523)	(28)
Accounts payable	(190)	202
Accrued expenses and other liabilities	(1,775)	(266)
Net cash used in operating activities	(1,247)	(2,031)
Cash flows from investing activities:
Purchase of investments	(1,990)	(8,848)
Maturities of short-term investments	4,860	6,800
Purchases of property and equipment	(33)	(1,239)
Net cash provided by (used in) investing activities	2,837	(3,287)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock plans	2,350	1,503
Net cash provided by financing activities	2,350	1,503
Net increase (decrease) in cash and cash equivalents	3,940	(3,815)
Cash and cash equivalents at beginning of the period	42,495	40,241
Cash and cash equivalents at end of the period	46,435	36,426
Non-cash financing activities:
Purchases of property and equipment through accounts payable and accruals	30	277
Supplemental cash flow information:
Net cash paid for income taxes	$ 111	$ 41