This weight-only electronic scale is perfect for letter & small parcel mail to ensure that you always pay the correct postage without overpaying. The low-profile design is easy to use & provides a 25 lb. capacity. Electronic scale can be powered by four AA batteries or by USB cable. Units key lets you toggle between kg, g & lb. / oz. Flip-up letter stand is designed to hold large envelopes. USB interface is designed to work with most of the current USPS application packages to print postage locally from a PC. The scale transmits weight via the USB cable to the PC, & the application program then takes the weight for postal calculations. Digital scale also features an on / off / tare key, auto shutoff & low-battery indication.