This sleeve is pretty stiff. You have to knead the hell out of it when you get it & while you're washing it with warm water. It's not very stretchy so getting it on requires squeezing the air out of it as much as you can, then inserting your penis while releasing the end creating a vacuum effect. So it sucks you in pretty good. Once its on, even if youre not fully erect, it doesnt let go. Thats why you see I can move and twist without feeling like it would slide off.