SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Computer equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Tooling
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Minimum | Equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years