This Texas Instruments electronic calculator is the TI-2500B model. Named the Datamath it takes 4 AA batteries and can be operated with either the batteries or the AC9130 wall charger. It has two settings. One for chain calculations and the other for construction calculations. Works perfectly. Comes with a black carry case. It measures 5.5" by 3" by 1.75". No damage that I can find, only very light soiling on the labels.