Vintage slide rules, aka analog calculators. These range from about the 1950s to the 1980s. Slide rules are now highly collectible.
Each comes with an original holder or box. Some include supplemental guides.
Priced per slide rule. See second pic for letter to select.
SKU: SL-3962
You can buy Slide Rule using cryptocurrencies: Bitcoin, Ethereum, Litecoin, Bitcoin Cash, Dogecoin.