The ShorePort Keel Roller Spacer Plate is designed to raise the roller another 1/2 inch if the rollers do not provide enough height in the forward position with the axle up.
With the many different designs of PWCs available, you may need to adjust the rollers to fit your specific watercraft. As a general guideline, raising the front and middle rollers makes it easier to unload the PWC. However, if the rollers are too high, the PWC may not stay on the Shoreport, and the rollers may need to be lowered.
Sold as a set.