The Metrel MI3311 GammaPAT has an inbuilt memory and can store up to 1700 test results which can be downloaded via USB into the Metrel PATLink PRO Software supplied with this kit. Using the keys you can enter an appliance ID number or description which are then downloaded with the test results. This number can even be set to increment automatically to save you time. The Metrel PATLink Pro is a good PAT software package that will store results and produce PAT certificates. The Metrel GammaPAT PRO is the LOWEST COST Downloading PAT tester on the market.