What do you use to raise the MH to work underneath?

I also use wood ramps, 2x12 stacked 4 high, 4' for the bottom layer, and angle cut where I drive on them. I made 6 identical and that gets the coach up 6". When I adjusted the air suspension I needed to make sure there was plenty of room to scoot under with air dumped. Gives plenty of room for that job, lubing, and other "under coach" chores.

I'm on the road on the way to AK and can't take pictures of them.