Never used one, though it sounds expensive. Alway's used hose insulation like one would get for a water hose at Lowes or Home Depot....When we camped this past thanksgiving and temps. got down to zero with a brisk wind on top of that, I alway's leave the faucet dripping water, it's alway's helped to keep from freezing up the line.
Jim & Kathy, (Boxers, Buddy & Sheba)
2016 Ram 3500 DRW Longhorn 4X4/CC/LB/Aisin/4.10/rear air assist ...Pearl White.
2016 DRV MS 36RSSB3/ W&D/ slide toppers/ DTV satellite/ 5.5K Onan propane gen.
B&W RVK3600 Hitch
Fulltiming in WV & TX
USAF 71-75 Viet Nam Vet