REVENUES

3 Months Ended

Mar. 31, 2022

Revenue from Contract with Customer [Abstract]

REVENUES

11. REVENUES

For each of the identified periods, revenues can be categorized into the following (in thousands):

	Three Months Ended
	March 31,
	2022			2021
Product sales	$	3,562		$	1,265
Maintenance fees		11			11
Professional services		26			4
Shipping and handling		181			99
Discounts and allowances		(10	)		(7	)
Total revenues	$	3,770		$	1,372

During the three months ended March 31, 2022 and 2021, 48% and 32% of revenues were derived from customers located in California, respectively. In addition, 4% of revenues in the three months ended March 31, 2022 were international sales compared to none in the same period in the prior year.

At March 31, 2022 and December 31, 2021, deferred revenue was $1.5 million and $0.3 million, respectively. These amounts represented customer deposits in the amount of $1.3 million and $0.1 million for March 31, 2022 and December 31, 2021, respectively and prepaid multi-year maintenance plans for previously sold products which account for $0.2 million and $0.2 million for March 31, 2022 and December 31, 2021, respectively and pertain to services to be provided through 2028.