The Amprobe AD40B is is a low-cost, miniature digital ammeter that measures AC current to 400 A with 10 mA resolution. The meter features jaws which open to 25.4 mm, data hold, autoranging and a 4000-count digital LCD display with bargraph. The Amprobe AD40B Ammeter won't take much ruch space in your tool kit and offers quick and accurate measurements.