Lippert 87220 Correct Track Suspension Alignment Kit Tandem/double axle alignment kit allows authorized Correct Track Service centers to correct axle alignment issues Bolt-on kit comes with everything necessary for double/tandem axle installation Adjustable axle hanger allows for 1/4-inch adjustments on each side of trailer/RV Adds 2 inches of height to trailer When properly aligned, tires will run smooth and cooler