Pentair/Sta-Rite 1-1/2" Slip and 2" Slip Pump Union (77703-0105) is a union and plumbing connection component for pool, spa, hot tub, or bath equipment repairs where the correct replacement part matters. This item is listed under Pentair/Sta-Rite and is intended for the Fittings & Valves: Unions category, making it easier to match the part to the style of component being serviced. Use it when the existing part is cracked, worn, leaking, missing, corroded, discolored, stripped, electrically unreliable, or no longer performing as intended.Before ordering, compare the product name, brand, category, and all identifying details with the part currently installed. Key fitment information includes part number 77703-0105. This is especially important on older spa and pool systems, where similar-looking Waterway, Hydro-Quip, Therm, Gecko, Raypak, Pentair, or other replacement parts may use different connection sizes, plug styles, face profiles, ratings, colors, or mounting configurations. Confirm the part number 77703-0105, dimensions, voltage or flow requirements when applicable, and installation orientation before completing the repair.This replacement is best used for pump, heater, filter, and equipment plumbing connections where thread type, slip size, and tailpiece style must match. Replacing the correct component helps maintain dependable system performance, reduce downtime, and avoid unnecessary equipment damage caused by poor sealing, restricted flow, loose electrical connections, or mismatched plumbing. For best results, inspect adjacent gaskets, unions, fasteners, cords, sensors, or housings during installation and replace any worn supporting parts at the same time. Genuine fitment focus for Pentair/Sta-Rite applications and related fittings & valves: unions service needs Reference replacement part number 77703-0105 when comparing against existing equipment or service documentation Match all visible specifications before ordering, including part number 77703-0105 Helps support reliable operation, proper flow, sealing, control, or alignment when installed correctly Professional installation is recommended when plumbing, electrical, heater, suction, or pressure-side systems are involved