GSPIRALBLISTER-S… 1 Order = 1 pack that contains 16 pins. Spiral Shelf Pins-Black. This shelf pin is spiraled shaped in designed so that it can be turned with a screw driver. As shelf pin is turned it will raise fractions of an inch to stabilize a wobbly shelf. Fits a 1/4 inch hole. Fine Tunable Spiral Shelf Supports are the answer to many common stability problems for shelves. One of the few adjustable support available on the market. Buy 10, 20, 50, 100.