Note 10. Leases

The Company has two operating leases for office and manufacturing space which require it to pay base rent and certain utilities. Monthly rent expense is recognized on a straight-line basis over the terms of the leases, which expire in 2027 and December 2021.

At September 30, 2021, the weighted average remaining lease term was 6.3 years. The operating leases are included in the condensed balance sheets at the present value of the lease payments at a 7% discount rate which approximates the rate of interest that the Company would have to pay to borrow on a collateralized basis over a similar term and amount equal to the lease payments in a similar economic environment, as the leases do not provide an implicit rate.

For each of the three months ended September 30, 2021 and 2020, operating lease expense and cash paid for leases was $0.1 million. For each of the nine months ended September 30, 2021 and 2020, operating lease expense and cash paid for leases was $0.4 million. Amortization for operating lease right-of-use assets was $0.1 million for each of the three months ended September 30, 2021 and 2020 and $0.3 million for each of the nine months ended September 30, 2021 and 2020. Variable costs were de minimis.

Maturities of operating lease liabilities as of September 30, 2021 were as follows (in thousands):