lot of early machine age industrial round red bakelite or catalin threaded knobs

Lot of three old industrial, machine-age, bakelite knobs. These old ball knobs are made from bakelite, catalin or another early plastic. These spherical knobs are an industrial, deep wine red color (not cherry red). They are opaque and each knob measures about 1 1/4" across the ball and have about 3/8" threaded mounting holes. These are in very nice vintage condition without chips or cracks.