Counts CO-9300 12-Digits Desktop Calculator has 99 steps to check and correct function. Backward and forward check function. Durable plastic body with a big 12-digit easy-view extra large screen display with acrylic cover. Auto power "OFF". Function keys: GT, CE, AC, +/-,√, %, (↑, 5/4, ↓), (F, 4, 2, 0, A), MU, Auto replay and 3 Memory (MRC, M- & M+) keys. Dual Power (Solar+Battery). Soft pressing buttons mechanism. Product Dimensions: 7.4 x 5.4 Inches / 187.96 x 137.16 mm.