It's fine thread lamp rod and it's 3/8" OD and 1/4" ID. I went to a hardware store and found it there. It's all over in various places, Lowes HD...look in the lighting section, quite common. Then I bought the smallest pipe nipple I could find. It threads on about two turns and is tight. Works for me. There's just enough diamenter in the garage door handle to accomodate a 3/8" bit. Also plenty of room in the grill strap. I then used butcher cord as a seal against the porcelain. This mod is simple, easy and effective. It looks nice and neat...no extra holes.