The 2-inch Aquascape Black Poly Bulkhead.

To be used in skimmers, pump vaults, in the top of fountains and through pond liners.

It features a 2-inch female pipe thread on both ends and is commonly used in Aquascape pond products, skimmers, and waterfall filters with 2-inch threaded sockets. 

All Aquascape products are manufactured to the highest standards for use with koi ponds and water features.