Backflow Preventer Insulated Pouch (5F) - Pressure Vacuum Breaker Cover - Winter Water Well Pump and Sprinkler Valve Insulation - Protects From Severe Snow and Intense Sun

This was not cheap, but fits great, super high quality, and solved the issue.

Fits perfect, seems sturdy. Make sure you measure circumference and divide by two, don't just measure lenght/width.

While the cover is not a perfect fit for my backflow preventer it still fits and looks very nice. It keeps the brass staying nice looking and helps keep the warmth in when the temperature gets low. It is very easy to install, and it covers the entire backflow preventer. It has been outside for almost 2 years and has held up very good. It is thick and is definitely worth the money to save your backflow preventer from corrosion and the element elements.

Easy to use, very good quality and cheaper than changing my pipes after a freeze.

This is a great product. We were experiencing really cold temps where our water in the morning would not get warm until the sun was out mid-day. Getting up for school and work became a struggle to get ready. We ordered this product and have had hot water every morning when we wake up (even when it was well below freezing for the past 2 weeks). I would HIGHLY recommend.

I bought two as I have an upside down "U Shaped" piping. I put one on each side. Good fit. Easy to put on and take off with Velcro.

Worked great in mild freeze (26 F). My area does not usually get much colder. Use it to protect sprinkler system valves and faucet that sticks out from house. Nice adaptable design allows slip on and slip off and grommets allow staking to ground so winds do not blow it off sprinkler valves.

Fits incredibly well over my irrigation system pressure breaker. Very happy with it and paid about half of what I would have at an orange big box store for a bag that was way too big.