NOTE 3 — SUPPLEMENTARY BALANCE SHEET INFORMATION

Accounts Receivable, net:

Accounts receivable is net of allowances for doubtful accounts of $4.0 million and $2.5 million and sales returns of $0.3 and $0.2 million at December 31, 2020 and 2019, respectively.

Inventory:

Inventory includes write-downs for excess and obsolete inventory totaling $0.8 million and $1.3 million at December 31, 2020 and 2019, respectively. Write-downs for excess and obsolete inventory resulted in expense of $1.3 million, $15 thousand and $0.1 million during the years ended December 31, 2020, 2019, and 2018, respectively.

Prepaid expenses and other current assets:

Property, Plant, and Equipment, net:

During the year ended December 31, 2020, the Company disposed of leasehold improvements related a property that was vacated upon lease expiration. The Company did not recognize any impairments on property, plant, and equipment during the years ended December 31, 2020, 2019 and 2018.

Accrued Liabilities:

The CARES Act allows employers to defer the deposit and payment of the employer's share of Social Security taxes through December 31, 2020. Under the CARES Act, the Company deferred $0.4 million as of December 31, 2020. The deferred liability is included in accrued payroll and benefits.