This is a great little masturbation sleeve and is one of my favorites - amazing for the price. The interior ribbing feels great on your cock - might be a little bit too much for some as a matter of fact. It stretches great for thicker dicks like mine. My two biggest suggestions for improvements are 1) make the exterior of it with some more texture or nubs - when the lube comes out (and it will), it is hard to keep a nice grip on it and 2) make it longer -while it feels great with your cock head slipping out the other end, it would be more sensous to be another inch or 2 longer.
Its like 4^ long so anything bigger than small is too big,average and big guys don't buy this. Plus there's no real pleasure in it, the ribs are small and theres not many of them. Personally this was a waste of money. Nothing like the real thing.