HC133 Replacement for the best selling Aurora HC101 calculator. Features and Benefits Robust handheld model with durable hard keys Large numeric keypad for easy viewing and entry Clear 8 digit LCD display 3 key memory Has +/- Change sign key Long lasting - solar powered with battery backup Auto Power Off to conserve power Notes Constants: Addition, Division, Multiplication & Subtraction. Percentage key & Square root. Dimensions (W x D x H): 70 x 115 x 15mm Weight: 50g Backup battery ref: LR1130 or BSR54H