If you look at the underside of one of your shelf pieces, you may notice either cutouts, or plastic clips that are a tell-tale sign of what type of pin you should use. Cutouts (or, small indentions if you prefer), are usually in the shape of the pin that fits properly, and keep the shelves from sliding when moving items on and off of them. If there are plastic clips, these are almost ALWAYS used with "PIN" style pegs, and are designed so that the snap into those clips. That type of pin is round on both sides, (the part that pushes into the holes on the sides, AND the part that clips into the underside of the shelf. Feature - Color: Silver - Material: metal - Size: 1.7 x 0.5 x 0.5cm - Bracket style shelf support - and durable for long time use - , with riveted pin - L-shaped Without hole - Perfect shelf support in book shelves, cabinets, etc. Package list: 60 x Shelf Bracket Pegs