The model dj 120 desk calculator has a 12 digit display solar amp battery power tax calculations other features are percentage calculations 3 key memory square root double and triple zero key general information auto power off two year maufacturers warranty dimentions mm 140w x 191 mml x 35h weight 205g power supply dual powered solar and battery design non stick plastic keys display extra large angled 12 digit display functions and features square root mark up