These shelf pegs are constructed of plastic and come in a clear finish for increased concealment. They are designed to receive 1/2 inch thick shelves and can support a maximum of 5 pounds each, These clear plastic shelf pegs are designed for 1/2 inch thick shelves and support up to 5 pounds per peg. The key feature is the self-locking tabs that secure shelves in place, preventing tipping and rotation. The 1/4 inch diameter pegs have a 5/16 inch depth and serrated stems for a stronger grip. For different shelf thicknesses, see Prime-Line U-9395 (5/8 inch), U-9397 (3/8 inch, 5mm diameter), and U-9398 (3/4 inch).To adjust the pegs, push and hold in the locking tabs while twisting the shelf upward. If lifting from the left, twist clockwise; from the right, twist counter-clockwise. This may require additional hands or using old credit/business cards to press the locking tabs in. After removing the shelf, the pegs can be relocated to a new height within the cabinet.