Heat: not left them in the sun so don?t know if you get that sagging or compression. My set up is a Lenovo T470S , bose companion series 3 speakers and using Camtasia S/w. I received a plastic bag with one each of a large, medium and small gel for the right ear and the same for the left ear. Now I have to pay 15. A lot of people said that you can endlessly keep tightening the lower bolts because there is no end to the threads/easily wrappable metal that is hollow (or along those lines). Disappointed (especially since no other reviews seemed negative), I took photos and sent in a request. I personally like it tied in the back but it does look cute tied on the side, as well. This product even though it lists for my vehicle type, says nothing about push button start only. I bought this new pair of Soludos for my upcoming trip to Paris and this is what I found as I opened the box to pack my suitcase today. I bought it mainly because I like this color.