June 30,

December 31,

2020

2019

Preferred stock dividends payable

$

2,901

$

2,901

Accrued compensation and related charges

2,762

3,307

Payable in connection with land restoration of Nanjing JinMei factory

693

703

Accrued income taxes

689

171

Advance from customers

520

396

Accrued professional services

458

630

Current portion of operating lease liabilities

382

319

Accrued product warranty

352

387

Current portion of royalty payments

300

—

Accrual for sales returns

90

26

Payable in connection with repurchase of subsidiaries shares

78

151

Other tax payable

62

50

Other personnel-related costs

55

180

Payable in connection with construction

46

1,447

Other accrued liabilities

1,123

1,013

$

10,511

$

11,681