Four stars, but do read on for the why. First, thank you for a product that keeps these six decade old hands from being frozen while snow skiing. I used them inside new Hestra gloves and while I won't say my hands were toasty, they were warm enough for skiing in the intermountain west where I live, and where skiing temps this time of the year run from single digits to the mid twenties. For this I would recommend them with a few caveats. The days I've used them started around 5 degrees and warmed to around 15 in the afternoon, for context. The battery pack sits inside the wrist and while that doesn't impede a pole plant, it did mean the gauntlet on the outer glove was very stretched and not easily pulled over the outer layer and the battery pouch. Also, it meant that I unknowingly changed the temperature setting several times. I will watch more closely in the future to avoid closing the coat cuff on the selector button. Other than those two items, the liner performed acceptably. My suggestion to ORORO would be to offer a slimmer battery pack with a reduced life, I believe this would be accepted. These could be easily switched out mid-day and then recommend moving the temperature controller to the back of hand to improve accessibility and away from outer wear cuff closure. Nevertheless, I would recommend the ORORO heated glove liners to keep those cold clear days on the skiing calendar.