I was concerned about my fill probe getting dirty sitting exposed while target practicing, so I designed a 3D dust cover. It fits loosely over the O-ring section but is a snug fit on the metal closest to the whip. I only had to print 3 before i got the dimensions correct, not bad for a rookie. I uploaded a file to thingiverse so anyone can print it. https://www.thingiverse.com/thing:7112912