Test voltage from 5 to 50 volts AC/DC. Easy to use: clamp alligator clips to positive and negative terminals or wire leads. Checks automobile, truck and heavy equipment batteries or generators and alternators. Also checks lantern batteries, razors, door bells and other small household appliances. 1" (2.54cm) numbers. 7-3/9"h x 3/5"w (18.5cm H x 1.4cm W).