The CRL Drill-Thru Shelf Support with Tensioner is designed to be used with the CRL Cable System for 3/8" (10 mm) Glass, and is used in single shelf installations. The Support requires a 1/2" (12.7 mm) drilled hole in the shelf, and is easily adjusted either up and down on the Cable to obtain the desired height. This Support can also be used with wood shelves using the three holes in the support disk to secure the shelf with wood screws (not included). The diameter of the Shelf Support Plate is 1-3/8" (35 mm). Each Drill-Thru Shelf Support has a maximum weight capacity of 20 lbs. (9 kg). The package contains one Support Disk and one Cable Tensioner.