B. Lessor arrangements We lease Caterpillar machinery, engines and other equipment to customers and dealers around the world, primarily through Cat Financial. Cat Financial leases to customers primarily through sales-type (non-tax) leases, where the lessee for tax purposes is considered to be the owner of the equipment during the term of the lease. Cat Financial also offers tax leases that are classified as either operating or direct finance leases for financial accounting purposes, depending on the characteristics of the lease. For tax purposes, Cat Financial is considered the owner of the equipment. Our lease agreements may include options for the lessee to purchase the underlying asset at the end of the lease term for either a stated fixed price or fair market value. We determine the residual value of Cat Financial’s leased equipment based on its estimated end-of-term market value. We estimate the residual value of leased equipment at the inception of the lease based on a number of factors, including historical wholesale market sales prices, past remarketing experience and any known significant market/product trends. We also consider the following critical factors in our residual value estimates: lease term, market size and demand, total expected hours of usage, machine configuration, application, location, model changes, quantities, third-party residual guarantees and contractual customer purchase options. During the term of our leases, we monitor residual values. For operating leases, we record adjustments to depreciation expense reflecting changes in residual value estimates prospectively on a straight-line basis. For finance leases, we recognize residual value adjustments through a reduction of finance revenue over the remaining lease term. See Note 7 for contractual maturities of finance lease receivables (sales-type and direct finance leases). The carrying amount of equipment leased to others, included in Property, plant and equipment - net in Statement 3, under operating leases was as follows: Payments due for operating leases as of December 31, 2020, were as follows: Revenues from finance and operating leases, primarily included in Revenues of Financial Products on Statement 1, were as follows: We present revenues net of sales and other related taxes. December 31, (Millions of dollars) 2020 2019 Equipment leased to others - at original cost $ 6,077  $ 6,208  Less: Accumulated depreciation (2,035) (1,960) Equipment leased to others - net $ 4,042  $ 4,248  (Millions of dollars) 2021 2022 2023 2024 2025 Thereafter Total $842 $494 $260 $134 $64 $64 $1,858 (Millions of dollars) Year ended December 31 2020 2019 Finance lease revenue $ 492  $ 521  Operating lease revenue 1,124  1,248  Total $ 1,616  $ 1,769  131