Summary

I made these in an attempt to isolate the sound of an electric fuel pump from the frame and body of my Jeep. They're made for 5/16 bolts but can be scaled for just about any size bolt or thickness desired. Proper installation is for the raised portion to go through the hole and the one with the inset goes on the other side, this will completely isolate the bolt from the frame. I used both 95a and 85a TPU with the latter being the most effective at noise reduction.