Love these!!!! They are thinsulate mittens with a soft glove like inside around your fingers (very comfortable, not too snug). The outside repels water nicely. Alone they are warm for basic cold temps but for the bone chill temps the heating element is awesome ...or when you just want a mini warming spa for your hands! My hand measured, rounding up, 7”cir & lgth and 3” middle finger? so I got the small. They fit my hands perfectly with a small pinch of room above ea finger (great for those who wear longer nails- not me). In addition to two adjusters for the wrist to tighten, they have a wrist leash, similar to ski gloves. The battery pocket is on the inside of the wrist & does not feel bulky or heavy with the battery in it. The battery is about 1.8”x2.5”x.5” and very light weight. There are 3 levels of heating that are easy to adjust even while wearing the mittens. I highly recommend these mittens! These and my Ororo vest make New England winters warmer with more opportunities for outdoor fun! Nice enhancements would be they make them machine washable like the apparel as opposed to just hand washing the surfaces and the wrist leash more adjustable.