The popular ULP-402 series plastic washers are made of high-grade polypropylene plastic with large ribs that stiffen plate and limit deflection. Features include pre-spotting central stem/tab for quick, easy pre-spotting into insulation board and 16 keyholes for mechanical locking of base coat. The ULP-402 fastener is 1-3/4in diameter and comes unassembled. Compatible with Wind-lock® high coated exterior fasteners. Consult system manufacturer for specific requirements.