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Note 4 - Balance Sheet Components - Summary of Balance Sheet Amounts (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | --- | ---
Cash and cash equivalents: |  |  |
Cash | $ 23,977 | $ 13,720 |
Cash equivalents | 68,390 | 82,315 |
Cash and Cash Equivalents, at Carrying Value, Ending Balance | 92,367 | 96,035 |
Restricted cash | 525 | 3,390 |
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance | 92,892 | 99,425 | $ 135,651
Inventories: |  |  |
Finished goods | 3,071 | 6,142 |
Raw materials | 1,047 | 1,249 |
Reserve for obsolescence | (339) | (987) |
Inventory, Net, Total | 3,779 | 6,404 |
Property and equipment: |  |  |
Office equipment | 449 | 578 |
Office software | 1,001 | 1,037 |
Machinery | 30 | 28 |
Furniture and fixtures | 254 | 327 |
Leasehold improvements | 839 | 1,001 |
Construction in progress | 41 | 0 |
Property and equipment, at cost | 2,614 | 2,971 |
Accumulated depreciation and amortization | (2,075) | (2,236) |
Property, Plant and Equipment, Net, Ending Balance | 539 | 735 |
Other accrued expenses: |  |  |
Sales returns | 189 | 373 |
Employee-related expense | 1,149 | 1,258 |
Warehousing, inventory-related and other | 584 | 756 |
Accrued Liabilities, Current, Total | 1,922 | 2,387 |
Deferred revenue: |  |  |
Deferred revenue | 3,091 | 4,506 |
Unshipped Product [Member] |  |  |
Deferred revenue: |  |  |
Deferred revenue | 1,005 | 2,390 |
Auto ship advances [Member] |  |  |
Deferred revenue: |  |  |
Deferred revenue | 1,977 | 1,985 |
Product and Service, Other [Member] |  |  |
Deferred revenue: |  |  |
Deferred revenue | $ 109 | $ 131 |

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