There is no specific fit guide for jack feet so you'll need to measure your jack feet to know which size will fit your RV.
For example if you have 10" jack feet you'll want the SnapPad Jack Pads for Class A and C Motorhome w/ 10" Octagon or Concave Round Jack Feet - Qty 4 Item # SP84FR4.
If you measure and reply back with what you have I can pick out the correct pads for you.
I've also attached our page of SnapPad sizes for your convenience. view full answer...