This air-cooled rheostat provides a variable resistance of 225 ohms with a maximum current of 1.2 amps. Oxidized constantan wire is wound on a vitreous enameled tube, and the sliding contact carriage, mounted on a slide bar, carries a phosphor bronze contact for long operational life. The unit features three binding posts: one at each end of the winding and one at the end of the slide bar for electrical connections. The rheostat measures approximately 12" in length. The tube size is 300 x 44mm. Suitable for physics classrooms and laboratories where adjustable resistance in electrical circuits is required.