AG100-001 Air Gap International Universal Air Gap for Water Softeners and Filters AG100-001 Universal Air Gap for Water Softeners and Filters with 1/2-inch OD or 5/8-inch ID Inlet Port and 1-1/2-inch or 2-inch Drainpipe Outlet The AG100-001 Universal Air Gap is designed to provide an effective way of connecting water softeners and water filters to 1-1/2 and 2-inch drain lines. The AG100-001 features a single inlet port that connects 1/2-inch piping or 5/8-inch tubing from a water softener or filter to the drain line. The unique feature of this air gap is able to accommodate 1-1/2-inch, and 2-inch standpipe drains with ease. Also, a unique design of this air gap enables the installation of multiple air gaps into the same drain connection. Up to 3 AG100-001s can be installed into the same drainpipe to provide a total of six simultaneous water discharge connections. The AG100-001 uses a special plastic material that provides a secure connection between piping, tubing, and drain line.