Make one. Just get a PVC cap and a silicone coupler and drill a hole in the top of the cap and insert a tire air thing.
I have a fancy one here that I got from one of the forum members. I'll take a picture and upload it, but you can do the same out of PVC pretty much.
I have a fancy one here that I got from one of the forum members. I'll take a picture and upload it, but you can do the same out of PVC pretty much.