This is a weatherproof outdoor 13 Amp fused electrical switch manufactured by British General. The switch is weatherproof to IP55 giving protection from water and dust when the cover is closed.
For connections there are 4 x M20 cut-outs (one on each side) and 1 x M25 cut-out, with a sealant ring, on the rear. 44mm fixing centres with horizontal and vertical adjustment.
The switch is easy to install and comes with installation instructions.