What this product does A fully assembled 3-inch sewer cleanout cap that expands to form an airtight seal in drain inlets and return lines. It blocks debris and external contaminants, prevents water intrusion, and protects pipe ends during use or storage. Why you need it Protects plumbing from clogging, pipe damage, and unwanted ingress during maintenance, storage, or seasonal closure. The tight expansion seal reduces the risk of leaks and keeps contaminants out of your system, saving time and repair costs. Key materials and construction High-grade rubber body for reliable expansion and sealing. Robust metal components for strength and durability. Stainless steel wing nuts instead of plastic for better stability and longer service life. Fully assembled — ready to install out of the box. Performance and compatibility Designed as a 3-inch expansion plug for most standard 3-inch cleanouts and piping systems. Creates a secure, airtight seal without adhesives or additional sealants. Suitable for residential and commercial plumbing applications. Ease of use Tool-free installation: tighten the wing nuts by hand to expand the plug and lock it in place. Quick removal and reinstallation for routine maintenance or testing. Typical applications (practical scenarios) 1) Pressure testing and plumbing maintenance: use the cap to isolate and pressure-test sections of pipe without water loss or contamination. 2) Pool and spa winterization or off-season storage: seal return lines to keep debris and wildlife out when equipment is not in use. 3) Construction, renovation, or storage units: protect sink and floor drains from paint, dust, and debris during work or while storing items. Benefits at a glance Prevents pipe breakage and blockages by shielding pipe entries from debris. Durable materials resist wear and extend service life compared with plastic-only designs. Hand-tightened stainless steel wing nuts provide stable, repeatable sealing. Ready-to-use 3-inch size fits most standard systems and saves installation time. Notes Intended for 3-inch cleanouts and compatible piping sizes. Follow standard plumbing safety practices during installation and pressure testing.