I use two on my two axle. They cut easily with a circle saw. I cut mine to just before the first circle from the narrow end. You'll love them after a couple times using them.
2000 F250SD SRW 7.3 Long Bed Extended Cab Air Bags
2014 Eagle 30.5BHLT
2007 Layton 245LF (sold)
196? Shasta 16ft
Learn from others mistakes, you'll never live long enough to make them all yourself.