Heavy duty and high grade EPDM washer with A2 stainless steel cap to provide a water-tight seal. Also known as a BAZ washer. Frequently used with self-drilling screws in roofing applications. High quality gradeUp to 180C temperature range"Diameter mm - N/AOuter Dia. mm - 25Colour - N/AFinish - N/AMaterial - Austenitic Stainless Steel (A2-304) Timco BAZ Washers - A2 Stainless Steel (Size 25mm - 200 Pieces) in Black Size: 1000mm x 1000mm