5. CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS AND SUPPLIERS

Concentration of credit risk

Financial instruments that potentially subject us to a concentration of credit risk are primarily cash equivalents and accounts receivable. We typically do not require collateral from our customers. As of September 30, 2021, our cash and cash equivalents are comprised of operating checking accounts and short-term highly rated money market savings accounts.

Concentration of major customers and suppliers

For the three and nine months ended September 30, 2021, one customer, Microsoft Corporation, accounted for $718,000 and $1.9 million in revenue, respectively, representing 100% of our total revenue, for each period. For the three and nine months ended September 30, 2020, the same customer accounted for $539,000 and $2.6 million in revenue, respectively, representing 84% and 96% of our total revenue, respectively.

Typically, a significant concentration of our components and the products we have sold are manufactured and obtained from single or limited-source suppliers. The loss of any single or limited-source supplier, the failure of any of these suppliers to perform as expected, or the disruption in the supply chain of components from these suppliers could subject us to risks and uncertainties including, but not limited to, increased cost of sales, possible loss of revenues, or significant delays in product development or product deliveries, any of which could adversely affect our financial condition and operating results.