The company guarantees these mitts to be the warmest you've ever owned. For me, they are. For several years now I’ve been using the Outdoor Research Alti Mitt. I’ve had success with these in temps down to around -20°F. They are advertised as expedition mitts and I must say that I’ve been thoroughly impressed with them for the most part. (note: my Alti mitts are an older model. The current model may have better insulation) Lately, I’ve been subjecting myself to colder outings (-20 to -30°F)… Full review
Superior Glove is a family company with more than 100 years in business making hand protection solutions and innovative gloves.