This is a plug protector that fits over the male end of a power cord. It will keep the contacts form becoming damaged in a shop environment. The original design was created by mausolfb and I found it to be very handy. After using some of these protectors, I thought ot myself, wouldn't it be nice if I could clip it to the cord when the tool is in use. So I modified the design so that it will clip to the round power cords typically found on power tools.