SummaryThis is for a pool from target. There is a rubber plug in the air fill hole and then a threaded cap that holds it in. This is a replacement threaded cap. This uses syvwlch's awesome thread library ( http://www.thingiverse.com/thing:8793 ) If you are going to compile the openscad file, you'll need to download that as well (and change the location in the scad file)InstructionsPrint it, screw it on.