The SL-300SV is a heavy duty pocket calculator which has an extra large and clear 8 digit display. It\'s dual powered (solar with battery backup) and functions include profit margin %. Additional features include plastic keys, command signs , 3 digit comma markers , 4 constants, auto power off and comes with a wallet for protection.Specification. 8 Digit Large LCD Display. Heavy Duty Professional Pocket model. 4 Key Memory. Solar Powered (with battery back-up). Percentage and Square Root Keys. Change sign Key. Extra large + Key* Alternative modelsIf you require a high functionality in a compact format try the SL-300VC