Lenz5.1 Toe Cap Unisex Heated Socks with rcB 1200 Batteries

Purchased as a gift for my wife. First pair was defective and one sock would not heat on its second use. Exchanged and have had no issues thus far with the second pair. Battery life is adequate and her feet and toes remain comfortable through a full day of skiing. They are comfortable. It should be noted that they do not give the sensation of wamth, but rather, her feet just do not feel cold. There are many options that are less expensive, sometimes I think I should have tried those options first. But these seem to be high quality and engineered well.