I was really surprised how effective the white bolero is on a hot sunny day. Not only was it effective in lieu of sunscreen on my arms and shoulders, but it kept me cooler than I expected as well. And it's much more comfortable than regular arm warmers. I ordered a size up to allow for ventilation.

in mississippi, riding means sun protection everywhere. These (in white) are cool even in the heat and so far no sunburn. I do wish I knew how UV-proof they were, and I do wish the arms were longer, to cover the back of wrists. (but I wear wrist bands with them-- I do have long arms)