This vintage Hewlett-Packard HP-21 calculator is a rare find for any collector or enthusiast of vintage electronics.

The HP-21 is a reliable and durable calculator that is perfect for anyone who enjoys vintage electronics. It has been well-maintained and is in excellent working order. This calculator is a great addition to any collection and is sure to be a cherished item for years to come. It runs off 2 AA batteries and polarities have been noted on the battery holder to ensure no damaging errors are made when swapping batteries.