Use these in the barn to keep the pipes from freezing. These work well. Easy to install. Top them with a fiberglass insulation - not just a foam tube. But worth the money to avoid plumbing problems in the middle of winter.
Used it to winterize my RV hose. I didn't even do a perfect job and it worked perfect. For a 25 foot hose I had enough length to out a couple wraps around the water fixture in the RV park too. Awesome.
Have these on all my hoses in our unheated New England garage. They work well and have given us piece of mind in single digit weather. Just make sure to exactly follow mfg's installation instructions.
M. Mooney 
