Concentrations and credit risk (Tables)

12 Months Ended

Mar. 31, 2021

Accounting Policies [Abstract]

Net sales to customers

The net revenue representing at least 10% of total net revenue are as follows:

	Year Ended March 31,
	2019				2020				2021
	$ in thousands		%		$ in thousands		%		$ in thousands		%
Customer A		3,715		37		3,573		27		3,633		23
Customer C		1,225		12		1,239		9		1,386		9
Customer B		1,027		10		313		2		619		4
Customer E #		996		10		—		—		—		—
		6,963		69		5,125		38		5,638		36

# Rental income from this customer ended as of February 2019.

The following customers had balances of at least 10% of the total trade receivables at the respective balance sheet dates set forth below:

	March 31,
	2020				2021
	$ in thousands		%		$ in thousands		%
Customer C		241		30		343		27
Customer B		133		16		160		12
Customer A		99		12		298		23
Customer F		95		12		197		15
				70				77