Financial instruments and related items, which potentially subject the Company to concentrations of credit risk, consist primarily of cash 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 three months ended June 30, 2020 included 26% and 58% (aggregate of 84%) from two customers of the Company’s total revenues.

The Company’s revenues earned from sale of products and services for the six months ended June 30, 2020 included 25% and 56% (aggregate of 81%) from two customers of the Company’s total revenues.

The Company’s revenues earned from sale of products and services for the three months ended June 30, 2019 included 13% and 13% (aggregate of 26%) from two customers of the Company’s total revenues.

The Company’s revenues earned from sale of products and services for the six months ended June 30, 2019 included 19% and 18% (aggregate of 37%) from two customers of the Company’s total revenues.

At June 30, 2020, there was no balance of the Company’s total accounts receivable, and one customer accounted for 100% of the Company’s total accounts receivable with an amount of $750 at December 31, 2019.