For use as series resistance or as a potentiometer. These
are slide wire type. Oxidized copper nickel alloy wire is
wound on a porcelain tube to provide perfect insulation.
Phosphor bronze contact provided on plated brass slider
rod to give rapid and smooth movement. Three brass
terminals are provided, one at each end of the wire and
the third at one end of the slider rod thus the rheostat can
also be used as a potentiometer. Resistance in ohms and
current carrying capacity is engraved. The end supports
have holes for mounting. Diameter of tube 56mm.