I have Merrilat cabinets that are 30 years old. I had to cut about an inch length to fit my splint. (The piece that contains the splint). The guide or rail I have has a slight curve at the back of the rail. Therefore I had to cut off the piece that contains the splint. Fairly easy to cut with a hacksaw. The hardest part was bending down to screw the bracket to the back of the wall unit exactly where it needs to be to allow the drawer to move properly. This setup requires body contortions and manual dexterity. Anyway, the mount itself worked great! It adjusts the thickness and height of my splint well.