Powder Actuated tile backer board washer in PE material is a unique fastener designed for the attachment of rigid foam insulation to concrete, masonry or steel base materials. The fastener is pushed through the insulation until it touches the base material and then it is fastened in place with a Hilti powder-actuated tool. The fastener can fasten insulation panels ranging in thickness from 1" through 4-3/4". soft washer with pre-mounted powder-actuated fastener is designed for attaching thin membranes or panels to concrete base materials. The washers are 30mm and 60mm in diameter with nail lengths of 1-1/2", 1-7/8" and 2-1/2". These fasteners are installed using a Hilti powder-actuated tool.