HP 40gs Graphing Calculator. Form factor: Pocket. Display size (HxV): LCD, Display resolution: 131 x 64 pixels. Battery type: AAA x 4 + CR2032, Battery life (max): 65 h. Weight: 0.249 kg, Size: 94 mm (3.7 "). Dimensions (WxDxH): 187 x 94 x 31 mm, Internal memory: 2.25 MB, Power requirements: AAA x 4 + CR2032