The U1403 is a silicone sealing boot designed to protect pushbutton switches from contaminants such as dust, sand, and water. Constructed from durable silicone, it features an integrated black knurled brass nut and offers excellent performance across a wide temperature range. This boot is specifically designed for switches with a Ø 6.35-40 NS (1/4-40 UNS) bushing, making it compatible with the 18000, 9000, and 13000 series. Its protective qualities ensure reliable switch operation in demanding environments.