I bought this to replace a broken pair of non-DTC gliders. They fit in the same screw holes as me. replaced. However, the rear mount is different. My original rear mount is plastic but allows for side to side movement. This means that if the mount isn't perfectly parallel, the movement will correct it. The original bracket also fits into two holes in the back of the case. The arm of this product is metal but does not move from side to side. That is, if the mount is not perfectly positioned, the slide tends to stick. Because the rear bracket is bolted, the installer must reach all the way into the back of the cabinet to locate, mark, and bolt the bracket. With a 21" drawer this isn't easy. While the instructions are limited, I find it important that the bracket is flush in the front and evenly spaced on the sides. It would be easier if wooden studs were used as magnetic bushings are used readily available for them. I installed these slides and they moved smoothly. Be sure to measure the thickness of your drawers on the side before purchasing. They will not work with 3/4" drawers as their information page specifically states. They work with 5/8" thick wooden crates.