Here are the stated dimensions for the unit.It’s just a section of a mat like you find a tractor supply and are typically used in machine shops for “anti fatigue “ mats to stand on , difficult to cut to size but possible. I cut mine just a shade bigger than the bottom on the idler motor. No need to attach it. Just layed mine down on concrete floor in corner of shop under the RPC control box and placed motor on it.
Ran it without it for a bit but my floor isn’t perfect enough and had little more vibration and the idler wanted to “walk” mainly from startup torque. Mat stopped all that immediately.
Let me know what size you want and I may have a piece I can send you. It will keep you from buying a whole sheet since it typically comes in 4x6 or 4x8 sheets. I’ll be looking around for where I put the rest of it.