This Drain Plug is ideal for replacement kayak drain plugs, fish wells, bait tanks, water tanks, coolers, ice chests or almost any application where a positive sealing drain plug is required. Constructed of black nylon and featuring an ''O'' ring for positive sealing, this Drain Plug?s fine threads maintain a tight seal under high vibration conditions. This self retaining drain plug mounts in a 1'' diameter hole with 2 number 8 countersunk stainless steel screws (not included). The back side of mounting flange is designed with a groove to hold sealant for positive water proof mounting. Mounting flange is approximately 1-1/2'' x 2''.