4.  Customer Concentrations and Accounts Receivable

Sales to E-Quad Power Systems Gmbh (“E-Quad”), one of the Company’s international distributors, accounted for 10% of revenue for the three months ended September 30, 2020. Sales to E-Finity Distributed Generation, LLC (“E-Finity”) and Cal Microturbine, two of the Company’s domestic distributors, accounted for 17% and 12%, respectively, of revenue for the three months ended September 30, 2019. For the six months ended September 30, 2020, E-Finity and Cal Microturbine, each accounted for 10% of revenue. For the six months ended September 30, 2019, E-Finity and Cal Microturbine, accounted for 15% and 11% of revenue, respectively.

Additionally, E-Finity accounted for 12% and 14% of net accounts receivable as of September 30, 2020 and March 31, 2020, respectively. The Company recorded a net bad debt recovery of approximately $0.1 million during the three and six months ended September 30, 2020 and 2019, respectively.