Basically, you snap and glue a hard slippery plastic on the existing sliding door roller rail ("Slide Rail") and the "Slide Guide" is inserted in the bottom frame of the door in front of both of the existing sliding patio door rollers with the groove facing down.
The groove of the "Slide Guide" straddles and rides on the "Slide Rail" (plastic covered roller rail) making the door slide straight, easily and quietly. Thereby the "Slide Guides" take the place of the sliding door rollers.

The "Slide Guide" Sliding Door Roller Replacement Kit comes with a rail splitting tube to make installation even easier on your exisiting sliding glass door roller rail.
The kit comes with shims to make sure they fit doors up to 11/16" wide. Additional shims are available if necessary.
Doors slide like new! Quiet too!
Designed for sliding glass patio doors with worn rollers but the sliding glass door track is in good shape.
If your roller rail has bumps or dips in it, IT IS RECOMMENDED to also purchase a 1/4 inch sliding door roller rail cover the length of your door so the "Slide Guides" have a straight, smooth surface to ride on.
Rail covers can be purchased in 3 & 4 foot lengths as the seams where the sliding door track rail covers butt together will be covered with the plastic "Slide Rail" tubing and shouldn't be an issue.
Kit comes with either a black or white "Slide Rail" and will repair one door up to 8 feet in length and includes glue and all installation hardware.