Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012
Concentration of credit risk
Federally insured limit	$ 250,000
Number of financial institutions which maintain a majority of the entity's cash balances	1
Activity in allowance for doubtful accounts
Balance, beginning of year	15,500	9,000
Provision for estimated losses	(6,500)	6,500
Balance, end of year	9,000	15,500
Net accounts receivable	985,770	1,427,966
Warranty claims activity
Balance, beginning of year	65,000	25,000
Provision for estimated warranty claims	4,000	264,000
Claims made	(14,000)	(224,000)
Balance, end of year	55,000	65,000
Inventories
Raw materials	1,843,357	1,603,231
Finished goods	1,136,945	1,002,777
Total gross inventories	2,980,302	2,606,008
Less reserve for obsolescence	(51,000)	(117,000)
Total net inventories	$ 2,929,302	$ 2,489,008
Accounts receivable | Customer concentration risk
Activity in allowance for doubtful accounts
Number of major customers	1	1
Accounts receivable | Customer concentration risk | One customer
Activity in allowance for doubtful accounts
Concentration risk (as a percent)	6.00%	17.00%
Accounts receivable | Credit concentration risk
Activity in allowance for doubtful accounts
Concentration risk (as a percent)	0.00%