This is a 38mm x 25mm fence bracket commonly used for pool & garden fencing. The parallel version is used when your fence is on flat ground and at a accurate 90d angle as it does not allow any allowance for movement in any direction. If you are on land that is hilly you may want to look at the vertical bracket or if your boundary is not a accurate rectangle (or square) then you may want to look at the horizontal bracket. It’s made from cast aluminium and supplied in a powder coated satin black finish.
Also please see our listing for the self drilling/tapping screws or wood screws that go with this bracket