This Rev-A-Shelf 432-WF42-3C 3 x 42 Inch Pull Out Between Cabinet Wall Filler Shelf Organizer revolutionized otherwise wasted space in your kitchen. Normally a filler or extra space is simply covered up with a decorative front， but with Rev-A-Shelfs line of fillers， it turns that otherwise wasted space into useful space. Fillers are intended to be installed in new kitchen cabinet construction and will not work in existing cabinets. This model is a 3-inch wide design and features adjustable shelves with chrome rails and full-extension ball-bearing slides and can support up to 100 pounds. Adjustable door mount brackets are included and required for operationDouble-check your cabinets opening (inside dimensions) to allow the best fit. Measure side to side (width)， front to back (depth or length)， and top to bottom (height). Double-check to make sure your product is within measurements and dont forget to take into account any obstructions (plumbing， hinges， etc.).