ELK Freeze Relief 4" - Use Between 1.5" Sump Pump Line to 4" Discharge Line - Pipe Transition that Relieves Water Pressure and Protects Against Pipe Bursting, Pump Failure and Flooding APPLICATION: Freeze Relief is a sump pump and discharge line protector that helps protect both your sump pump pipes and discharge line pipes from freezing related risks like pipe bursts, pump failures, and flooding. HOW IT WORKS: Allows excess water and pressure to escape from the discharge line system to protect against water and pressure backlog that leads to line and pipe damage, pump damage, and flooding. INSTALLATION: Easily install in-line as the transition between 1.5" sump pump PVC pipe and 4" discharge thin wall SDR 35 pipe. DURABILITY: Made of high-grade polypropylene (PP) to withstand heavy use and is minimally impacted by the degradation effect of weather. Will hold up much better than comparable products made of PVC. COMPATIBILITY: Freeze Relief is compatible with standard sump pump 1.5" PVC pipe and standard 4" SDR 35 sewer pipe. Freeze Relief is a high-grade and extremely durable pipe transition product that relieves water and water pressure and helps prevent your sump pump and discharge lines from failing due to freezing weather. In the event that the sump pump and discharge line pipes are frozen or are otherwise clogged, Freeze Relief allows water and pressure to escape via the in-line pipe vents which will help prevent system backlogs, pipe bursts, sump pump failures, and flooding. Installation is quick and easy in-line as the transition between the 1.5" sump pump PVC pipe and the 4" discharge thin wall pipe.