I've been wearing these sleeves (and also gloves) for many years. I don't much like sunscreen (I've tried all kinds) so this has been a happy alternative. Seems like they would be uncomfortable on hot days, but in fact that's not the case, they're always quite comfortable. I wear them for everything: driving, gardening, hiking...any time I'm outdoors, or my skin is exposed to the sun. I wear the gloves in cooler weather when I'm wearing a long sleeved shirt or jacket. While I'll continue to buy these, there are some issue which resulted in 3 stars vs 5 stars. I wear a medium, and when I first wear them they fit well. However, over time they stretch out, and sag. I recently read on SkinCancer.org's website that "sun-protective clothing may lose its effectiveness if pulled too tight or stretched out, if it becomes damp or wet, or if it is washed and worn repeatedly." So, be forewarned. I don't know if any clothing is rated higher than UPF 50, but I mistakenly thought I was getting "total protection" from these sleeves. My error, not Eclipse Sun Products'. I had thought, given how much I wear these, that I would notice a contrast in my protected skin (arms) from unprotected (fingers), but that's not the case. My arms have ended up looking tanned. It could be that the UPF is not as high as I need, or the fabric is stretched and not providing adequate protection. But, these are better than nothing, and I don't get sunburned. There are a couple of products on the market that I've read about, but haven't yet tried that can also help provide sun protection. One is Rit Sun Guard Laundry Treatment UV Protection ( I saw this recommended on SkinCancer.org's website). Another is Sunsafe Rx capsules or similar (a dermatologist made me aware such products exist). Be safe in the sun! 06/08/2016 update: I've had occasion recently while working outdoors to wear these every day, working long hours in the sun for about a week. I ended up with a "T-shirt" kind of tan; that is, where my T-shirt covered my shoulders was untanned, where the sun sleeves were I was tanned. Yes, far better than nothing, but they don't provide total protection the way a denim or canvas shirt will. UPF 50 means "lets in 1/50th of the sun's UV." I think these are great for casual use--hiking on a partial shady trail, shorter times in the sun--but don't count on them for all day, every day, long sun exposures to keep your skin untanned, such as a long day at the beach. The tanning is subtle, but it's there. I've also found these last at most 2 years before getting too saggy to wear. I recently found another pair of sun sleeves that fit like a second skin and have no seam, which was wonderful. Cheaper too. I'll end up using both brands of sun sleeves. 11/29/2016 UPDATE - I hate to say this, but these sleeves didn't even last a year before they started sagging all the time. My prior comment of "at most 2 years" was based on a faulty recollection. The manufacturer had said "3 years" as I recall, with regular use (in the comments). I do use these all the time, and by all indications I have the right size. Now they are sagging all the time, they won't stay up for very long. When I launder them they're better for a short time, before the droop again. I'd buy these again, because I like them, but these are best for occasional use. Otherwise, they're kind of expensive for what you get. I've dropped the rating because of that issue.