yarixa wrote a review of Hotronic Footwarmer S4 Universal on February 26, 2018
Familiarity: I've put it through the wringer
These foot warmers were game changers for me. Took me about 5 min each boot to install. There is a YouTube video that walks you step by step through it. Love them my feet always get cold, and these have made a huge, huge difference in my ability to stay out and ski. My only regret is not buying them sooner.