We found all of the above links provided by @MyZettel to be a good read and very helpful to us understanding our twins.

BTW again, We bought 10 feet of clear plastic flexible water line from Home Depot and cut it into 10-20 biting tubes. This was exactly the same kind of tube that OT had given to us. Eric still chews them to this day.

try use Communication Board for Non Verbal and Autism with Basic Low Tech AAC Picture Cards by Etsy there so much choice..

If your Child gets OT you should ask if they can help you get a biting tube or you can get one at a safety store they are like $8-$10

BTW - our school district does provide something called "arm socks" to prevent arm biting. In our case, we had one twin biting the other, but I have seen them work on another student who was self biting. I think one can make arm socks by simply cutting off the toes on a pair of thick socks. Good Luck.