Anyone know what this thing is?
The brass knob unscrews to reveal a ?4mm threaded stub.
The two halves unscrew from each other - there's a ?3mm threaded shaft that goes about 8mm into each half, with the brass disc in the centre.
The brass knob unscrews to reveal a ?4mm threaded stub.
The two halves unscrew from each other - there's a ?3mm threaded shaft that goes about 8mm into each half, with the brass disc in the centre.
