Bought 3 for Christmas presents and we absolutely love them. They warm up extremely quick and very hot (don’t burn yourself) I suffer from “popsicle” fingers and this warms my hands up so fast even working on the farm in the snow

Funciona perfectamente!

Gosh this is SO SMART, charges fast, holds a charge, stays nice and warm, great product for my baseball player for the cold practice days!

I bought one each for my entire family and we all love them.

Second time purchasing, first one lasted 4 years. Great to have on those cold days.

This is great for me because my hands get really cold especially when working at the office and at the computer. However, I have noticed that the battery life is very short. Still worth it to me because again it does help, but just wish it would last longer because it does take a long time to charge.

Bought as gifts. My husband loves it and has found several uses for it. Our son enjoyed it on the 1st cold streak in here in Texas.

BACKGROUND INFO: I charged this product as soon as I received it to use the next day. I was using it the very next morning and there was a brief moment where it just turned itself off. After about 8 seconds, it turned itself back on. Slightly worried, I messaged KareCel about safety concerns, and they responded within 12 hours assuring me that everything was fine and they sent me another one without me asking completely free of charge! I've been using this hand warmer for two weeks now, and that initial shut-off glitch hasn't occurred ever since.BATTERY: The battery life is alright; I'm estimating around just a little above 2 hours over multiple days throughout the week. I wish it lasted longer. I guess generating heat pretty quickly takes a lot of energy if you think about it. It takes over 3 hours to charge. I tried to watch it while I'm charging it at night to see when the charging indicators are all full, but I get home pretty late and go to sleep fairly early. The manual states that the 3 lights indicate the battery life in 33% segments (1 light = 1-33%, 2 lights = 34-66%, 3 lights = 67-100%), but it usually drops to 2 lights after the first 10 minutes of use. The indicator isn't really reliable, but at least you'll know you'll have to charge it soon when it sits at 1 light for a while.HEAT: I've read other reviews that say this product gets really hot, but I think it's all relative. I will say that it produces a sufficient amount of heat that doesn't hurt but completely warms my hand. I alternative hands in about 10-second splits, and they're completely warm before 15 minutes. There are also 3 levels of heat; the heat indicator is red (unlike the blue light I failed to mention above) and stays lit while it's on. I honestly can't feel the difference between the heat levels; when your hands get warm, it's pretty difficult to tell the difference between the different settings. However, I assume more energy is being used at the highest heat level. That being said, my big-brain strategy is to start at the highest heat level for minute 1, drop it to the middle heat level for minutes 2-3, and switch to the lowest heat level for the remainder of the time! Regarding how long it takes to heat up, you can start feeling it after about 15-30 seconds depending on the ambient temperature.AESTHETICS/FEEL: Honestly, the product looks pretty cool. I ordered the black one, but it appears that all of them come with the light-blue-colored, felt-material carrying case. The texture is as expected; the heated part feels like a grip-y silicon, and the white part is just smooth plastic. The weight of the product makes it feel like a high-quality product.SUGGESTIONS: It'd be great if the battery life indicator was actually proportional in size, but it's not really a deal-breaker. My second suggestion is probably asking for a bit much, but a mechanism that stops the product from charging would be nice when it hits full charge. Of course, having that feature implemented would probably push the cost up. My final suggestion would be to have the case color match the product color. XDCONCLUSION: The product itself met my expectations for the most part; it keeps my hands warm. (I've used it in temperatures ranging from 37-55 °F so far.) I docked a star off just for the overall characteristics of the battery that I mentioned above. The customer service far exceeded my expectations. While their English wasn't perfect, the response time and quality of the response was phenomenal. The first response was within 9 hours, the next response within 6, and the successive responses after that were within minutes.