Casio 12-Dgt Desktop Calculator,Tax/Exchange,4-3/4"x6-7/8"x1-2/5" This 12-digit dual power desktop calculator with tax and exchange functions features a large, easy-to-read display and plastic keys. Functions include a three-key independent memory, cost/sell/margin, grand total, key rollover, percent, Profit Margin percent, change sign, double zero key, round off, cut off, ADD mode, three-digit comma markers, back space and auto power off. Calculator has a kick stand for easy desktop use. Power supply is Solar Plus with battery backup. Weighs 6.4 oz.