The 1-½” Brass Sight Glass Assembly is designed to visually monitor water or fluid flow in pool, spa, and industrial systems. Its durable brass body and clear glass window let you quickly check flow, clarity, or fluid levels without disassembly. Commonly used on commercial and residential pool equipment, this sight glass supports reliable operation and easy maintenance. Threaded connections make installation straightforward, and replacement glass, gaskets, and hardware are available for long-term service.