AIM Sports Real Shooter Rubber Stock Shoulder Pad for M4 / CAR-16 LE Stock.

"This is a real-deal shoulder pad, so no complaints there. You should know that these are made one-size-fits-all though, so if you're thinking that it will fit snugly on an M4 stock, you will be slightly disappointed. There's some "play" to it. It's real though- so if you want it snugger, you're looking for something that isn't made for real firearms.

"This is a good piece. I put it on a cheapie A&K S-System and it makes the hard plastic stock MUCH more comfortable.

Fits well, with a little play. Inexpensive upgrade.

Recommended. 4 stars because it is a little loose

"This shoulder pad takes your low quality LE stock and transforms it into one of the most comfortable things that will ever touch your shoulder. This thing feels GREAT. It is extremely comfortable and easy to install. I gave it a four however, because it's not super snug on the stock, it has some play in it. I don't foresee it falling off in the middle of a skirmish, though, so it should do you good. Highly recommended if you'd rather spend $12 on a good stock rather than $100.