Large SuperView display with 8 digits. With color coding and large buttons for optimal user comfort. (+/-) key for easy entry of negative numbers. Memory and % key. Key for changing plus/minus sign. Square root test. The protective cover can be slid onto the back of the machine. Ft 1.8 x 8 x 14.5 cm (h x w x d). Works on solar cells and batteries (1 x LR54 included).