This economy buzzer is great for science fair projects. Works on 1.5 V DC (any AA, AA, C or D battery will do). Create your own circuits or test batteries and solar cells with this buzzer. Connect it to a battery and a key switch to make your own Morse code circuit. Includes attached leads, one red and one black, 4" (10mm). Buzzer housing includes two screw holes for mounting. Buzzer size: 1"x1/2"x1/2" (25x13x13mm).