Quarterly report pursuant to Section 13 or 15(d)

Schedule of Deferred Revenue (Details)

v3.21.2
Schedule of Deferred Revenue (Details) - USD ($)
Jun. 30, 2021
Dec. 31, 2020
Multiemployer Plan [Line Items]    
Total $ 233,000 $ 331,000
0-12 Months [Member]    
Multiemployer Plan [Line Items]    
Total 112,000 169,000
13-24 Months [Member]    
Multiemployer Plan [Line Items]    
Total 74,000 84,000
Over 24 Months [Member]    
Multiemployer Plan [Line Items]    
Total $ 47,000 $ 78,000