The Ritchie Drain Pipe, part number 11471 is used in all Omni 1, Omni 2 and Omni-2 special units to drain water from trough away from the waterer. Add the Drain Pipe Guard part #17500 for added protection against the heat elements. Pair with Drain washer package #18075 (sold separately) to ensure a tight seal along the trough.