Also helps with the noise isolation. Very very tight, now I have to leave it in there because its too hard to get out. bought these to be used in my small acoustic trio. Great product but I shouldnt impulse buy. its a little off measurement but still a great item. Also assembly took like 5 to 10 minutes and anybody can do it. I figured when the first one stopped working I just had a faulty one, but when the second one broke when I didn’t even do anything to cause it to break, it sucks. They are comfortable and the charge lasts longer than I could ever watch TV in one day. It was longer than the original and it had a different plug If you dont make it tight enough every time, you risk scratching your frame with a bolt that has pretty sharp and deep threadng, and even severing your rear brake line, as that usually goes under the down tube.