Here is a picture and install instructions.

http://www.lag-shield.com/?engine=ad...FTNyGgodTmSejQ

Yes, even the Home Depot zombies will know what you are talking about. As for the rubber pads, go to a rubber supply and get enough rubber to make some 3inch squares ......if you have a three legged compressor, make three. Cut the hole in the middle for your lag bolt. If you cant find thicker rubber, stack a couple of layers up. Graingers sells machine mount pads with the hole in them.... I think they are 4 inches square.

The lag shields and bolts should cost less than $5 and the rubber pads about the same. The most expensive part is the concrete bit to drill the hole.

mike in tucson