This replacement knob was designed to help people with hand function impairments. It will fit most appliances where the shaft sticks out at least 1 cm. The insert uses 12 mm 4M screws that tighten onto the shaft and then the knob slips over top and fit snugly.
There are two inserts available, one with the centre hole all the way through for longer shafts and one that has a solid top for buttons that require to push and then turn.
There is also a version for people without mobility issues