OK, I'm really just posting this to see if I have the picture-posting thing down. It may help someone, though. The cap on the indicator on my changeover regulator fell off. It needs to be covered because it's vented and rain gets in there if it's not covered. I added a cap that was for 1/2-inch PVC pipe. It fits perfectly. A couple of dabs of silicone keep it in place and still let air in and out as needed. ...all for the princely sum of 38 cents.