The thumbscrews are approx 26mm long, of which approx 15mm is threaded M4 x 0.70 pitch. The head is milled round the outer edge.
The wall lugs are 10mm hexagonal, tapped with a single M4 x 0.70 pitch hole; there is a cast threaded lug (approx 9.5mm x M5 x 0.8 pitch) on one end to screw it into the resonator rim wall.
The mounting brackets are T-shaped; approx 47mm long with 2 x M4 holes at approx 37mm centres. The 10mm approx thumbscrew fixing slot is central in the 17mm wide "leg" of the T.