The Company leases office and warehouse space primarily in three locations: Del Mar, CA; Burlingame, CA; and Edwardsville, IL. As each contract does not meet any of the four criteria of ASC 842 for financing lease classification, the Company has determined that each lease arrangement should be classified as an operating lease. The right-of-use assets and lease liabilities for each location are as follows (in thousands):

	March 31,		December 31,
Right-of-use assets:	2021		2020
Del Mar, CA	$	579	$	613
Burlingame, CA		23		99
Edwardsville, IL		228		251
	$	830	$	963

	March 31,		December 31,
Lease liabilities:	2021		2020
Del Mar, CA	$	608	$	641
Burlingame, CA		28		109
Edwardsville, IL		229		253
	$	865	$	1,003

The Company’s leases generally do not provide an implicit rate, and, therefore, the Company uses its incremental borrowing rate as the discount rate when measuring operating lease liabilities. The incremental borrowing rate represents an estimate of the interest rate the Company would incur at lease commencement to borrow an amount equal to the lease payments on a collateralized basis over the term of a lease within a particular currency environment. The Company uses its incremental borrowing rate as of January 1, 2019 for operating leases that commenced prior to that date. As of January 1, 2019, the Company’s incremental borrowing rate was 5.25%.

Lease expense for these leases is recognized on a straight-line basis over the lease term. For both three month periods ended March 31, 2021 and 2020, lease expense was approximately $0.1 million. Undiscounted future minimum lease payments as of March 31, 2021 that have initial or remaining lease terms in excess of one year are as follows (in thousands):

2021 (remainder of year from April 1, 2021 to December 31, 2021)	$	231
2022		278
2023		218
2024		177
2025		30
Total undiscounted future minimum lease payments		934
Less imputed interest		(69	)
Present value of lease liabilities	$	865