The Sentry dual powered solar calculator with a back-up battery for low light conditions and an 8 digit display is easy to use at home school office or for travel. The calculator convenient size makes it easy to fit into a pocket purse or backpack. Brand Name: Sentry Color: Black Number of Digits: 8 digit Solar Powered: Yes Product Type: Dual Power Calculator Model Number: CA338 Batteries Included: Yes Display Type: LCD