My fingers are toasty warm on even the coldest days. Only critique is that the strap over the back of the hand was about and inch too short by design and slipped out the plastic buckle.
Mittens are very warm flying down the mountain in 15 deg f temps. They feel great, very warm on a 5°f walk. Look good with my yellow beanie cap.
The wiring connecting the batteries seems well made and substantial. The gloves come with a single charger that can charge both batteries at one time. I highly recommend these gloves.
Once these are on, they fit perfect and the stretch in the glove is comfortable. Not too bulky. They provide a nice, snug fit.
The material is stretchy and it fits my hand well. The battery is somewhat large, but it goes under the wrist.
Good fit, but warmth is barely detectable. The positive reviews are fake. Zero help keeping fingers warm.