Mac's Tie-Downs 700007 18" Round Chassis Stabilizer Mac's round Chassis Stabilizer is 18 inch in diameter and 10 inch maximum height Working height from 1.75 inch deflated to 10 inch inflated with only 20 psi Includes hose, ball valve, and 25 psi safety blow-off valve Great for reducing wear on suspension components when trailered Made in Idaho