1" Plug kit can be used with Rubbermaid water tanks. Can be installed with up to 2" hole diameter. Bulkhead requires a minimum 1-3/4" hole BUT no bigger than 2" hole NOTE: 1" Plug has an OD of 1.25". This 1" bulkhead OD is 1-3/4" and requires 1- 3/4" hole saw to install bulkhead. Locking Nut is REVERSED THREADED. The Best Bulkhead Fitting in its class with OVERSIZED Locking Nut High premium virgin PVC material with whopping 5mm THICK silicon seal gasket Excellent substitution with OEM Rubbermaid stock tank drain valve kit. Perfect solution for large oversized water barrel tanks. 1" FEMALE NPT Bulkhead. Drill 1 3/4" hole to install Upgrade your water storage containers with our robust 1-inch Drain Valve Kit, crafted from premium, thick-walled PVC for durability. This kit includes a female NPT bulkhead fitting, requiring a 1-3/4 inch hole for installation, and features a 5mm thick silicon seal gasket for a secure, leak-free seal. The oversized, reversed-threaded locking nut ensures easy installation and removal. Perfect for Rubbermaid tanks, rain barrels, and large water tanks, this kit is an excellent OEM replacement for Rubbermaid stock tank drain valve kits. Available in a sleek, black finish.