Radiator Knob, different internal square sizes

This model is a 3D-printed replacement knob designed for old-style radiator valves, faithfully replicating the original part both in shape and fit. It's ideal for restoring functionality to vintage heating systems without needing to source hard-to-find parts.The inside square diameter comes in 6, 7, 8.5 and 9mm, just the correct file. The internal structure is reinforced for strength and stability, with precise dimensions to ensure a snug fit onto the valve shaft. This version has been tested to replace the original metal or plastic knobs often found on older radiators.