The metal wall trim is predominantly used to professionally terminate flat roofing membranes at wall abutments. The trim slots into the wall chase (angle-grinder required) and the chase is sealed with black mastic/sealant to create a watertight seal. Each trim comes with 4 self-sealing hex fasteners used to fix the trim to the wall (wall plugs required - not included). The trim can also be used as a drip trim on flat roof and can either be fixed from the side or from the top