Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2023

Commitments and contingencies

Schedule of rent expense

The Company utilizes leased facilities and operates equipment under non-cancelable operating leases through July 2030. Below is a table of key properties:

			Lease
	Annual		Expiration
Location	Rent		Date
Baton Rouge, Louisiana	$	30,000	5/2024
Champaign, Illinois	$	609,000	12/2024
Champaign, Illinois (2nd location)	$	349,000	9/2026
Charlotte, North Carolina	$	38,000	5/2025
Escondido, California	$	238,000	6/2027
Long Beach, California	$	28,800	2/2024*
Ontario, California	$	174,000	12/2024
Riverside, California	$	27,000	Month to Month
Rantoul, Illinois	$	36,000	Month to Month
Smyrna, Georgia	$	492,000	7/2030
Stony Point, New York	$	118,000	6/2026
Woodcliff Lake, New Jersey	$	236,000	8/2027