I got mine a while back direct from Air Force. I don’t remember what they charged me for it but it was pretty cheap.
Here is what I did when I put mine on.
Start with the bottom half first or you will be SORRY. I got some rubbing acohol and soaked a cotton ball with it and liberally (I hate that word) smeared the inside of the cover. After a few seconds it slid on easily. Did same with the top half and it worked like a charm. But once it’s on there is NO ADJUSTING whatsoever. That’s why I say you MUST start with the bottom half first and have it seated. The two halves have to meet at a given point. If you put the top half on first and pull it down to far you are F$#ked.
If you have an aircompressor or access to one you can remove or install the air cover in a few seconds. Just shoot air into the bottom covers hole and slid on . And for he top one shoot air under the cover and slid it on.
i am an old bmx biker and to put the grips on the bars we used cheap hair spray, we put some on the grips and slid it on the bars and used compressed air to dry the hair spray, they would never move after that