GLIDES: The Hidden Glides on the ULTIMATE Sliding Shelf are 3/4-extension (not available in Full-Extension) and pull out about 16-1/2".  Sliding Shelf glides have been tested through 100,000 open/close cycles , are  rated at 100# load (75# dynamic).  Like all of our products, the glides on our ULTIMATE Slide Out Shelf have a limited lifetime warrantee. SIDES: ULTIMATE Sliding Shelves are 22” long front-to-back. Sturdy shelf sides are 5/8" thick, 3" high Furniture Grade Red Oak plywood.  Edges of plywood are also Oak veneer so no exposed plywood edges are visible when using the shelf.  CORNER JOINTS: The corners are fastened together using GLUED BISCUIT JOINERY.  Way stronger than any rabbet joint. SHELF BOTTOM: The shelf floor is 1/4” Hardwood plywood, dado-captured and glued in place.  No particle board, MDF, or other weak manufactured material is in ANY of our Sliding Shelves. SELF-CLOSING: The Ultimate Sliding Shelf closes automatically when within 1-1/4" of the cabinet. FINISHING: Sliding Shelves are hand sanded, ready for staining or painting, and are pre-assembled. INSTALLATION: When your ULTIMATE Sliding Shelves arrive, just fasten them to the cabinet floor or to any permanent shelf of your cabinet. We furnish the screws.  All you need is a screwdriver and about 15 minutes to install them. Ordering Special Sizes:  You may specify any width from 6" to 36", but special lengths below 19" require longer lead times.