Financial instruments and related items, which potentially subject the Company to concentrations of credit risk, consist primarily of cash, cash equivalents and trade receivables. The Company places its cash and temporary cash investments with high credit quality institutions. At times, such investments may be in excess of the FDIC insurance limit.

The Company's revenues earned from sale of products and services for the year ended December 31, 2019 included 33%, 21%, 17%, and 15% (aggregate of 86%) from four customers of the Company's total revenues.

The Company's revenues earned from sale of products and services for the year ended December 31, 2018 included 13%, 18%, 22%, and 20% (aggregate of 73%) from four customers of the Company's total revenues.

At December 31, 2019, one customer accounted for 100% of the Company s total accounts receivable with an amount of $750, and three customers accounted for 44%, 17% and 32% (aggregate of 93%) of the Company's total accounts receivable at December 31, 2018.