6. ACCRUED EXPENSES

Accrued Compensation

Accrued compensation included estimated year-end employee bonuses and related employee costs of approximately $5.4 million and $3.9 million at December 31, 2021 and 2020, respectively.

Accrued Warranty

The Company provides a limited warranty generally for one year. Estimated warranty obligations are recorded as an expense upon customer acceptance of related products. Factors that affect the estimated warranty liability include number of products accepted, historical and anticipated rates of warranty claims, cost per claim, and vendor-supported warranty programs. The Company periodically assesses the adequacy of our recorded warranty liabilities and adjusts the amounts as necessary. The amount of liability recorded is equal to the estimated costs to repair or otherwise satisfy claims made by customers.