Construction 9 ply Baltic Birch for the front, back, and sides. Butt jointed corners. Ready-to-finish. Blum 3/4 extension slides. Worthwhile Convenience Use sliding shelves to organize any room, then wish you got them sooner. Shelves are compatible with binning divider strips for even more organization! Shelves That Slide - Over 25 Years of Experience We prioritize both quality and customer satisfaction. Full extension slides are available, but not always recommended. We find that 3/4 extension slides are a great slide choice for most lower kitchen cabinet storage. 3/4's are easy to install, and have a lot of mounting options available. If you have any issues at all, please reach out to us. We have manufactured shelves for decades and would love to help.