4. REVENUE (Tables)
12 Months Ended
Dec. 31, 2019
Revenue from Contract with Customer [Abstract]  
Revenue from contracts

The following table provides information about disaggregated revenue by primary geographical markets and timing of revenue recognition for the years ended December 31, 2019 and 2018 (in thousands):

 

   Year Ended December 31, 
   2019   2018 
Primary geographic markets          
North America  $188   $ 
Europe   187    226 
Asia Pacific   158    20 
Total  $533   $246 
           
Timing of revenue recognition          
Products and services transferred at a point in time  $378   $176 
Products and services transferred over time   155    70 
Total  $533   $246