Calculated Industries KitchenCalc 8305 PRO Master Chef Edition Recipe Conversion Calculator with Dual Digital Timer Recipe scaling and portion sizing functions easily calculate increases or decreases in the size of recipes and portions Dual digital timer feature keeps elapsed time even while doing other calculations Measurement conversion feature quickly converts U.S. and foreign weights and measures (in fractions or decimal values). Auto shut-off Includes soft, clear plastic cover to protect keys during use. One long-life lithium battery and user's guide also included.