Black coated steel base plate 40mm in diameter with 23mm internal diameter. Four M3 threaded holes - two for attaching the TS82 switch to the plate and two for fitting the plate to a surface with 1/2" max surface. For thicker wooden dashboards, relieve the M3 threads and use a 4 gauge (2.9mm) screw. Supplied with two M3 x 16mm pan head screws for attaching the switch to the plate, and two M3 x 16mm countersunk screws and nuts for attaching the plate to the surface. For an alternative mounting plate that enables mounting to a Lucas S58 type column stalk, please see part number TS82-S58.