The cold glue puck is a true time saver. It currently comes in fives sizes and 2 shapes. There is a small, round puck that has a diameter of .497 inches. The medium, round puck has a diameter of .80 inches. The large, round puck has a diameter of 1.24 inches. The other shape is a rectangle. The small rectangle has a surface that measures .620 inches X 2.958 inches. The large rectangle has a surface that measures 1.250 inches X .988 inches. Each puck has a lock hole for tightening down the puck in your slide hammer. It has a lock nut that allows you to lock it into your slide hammer. It is a snug fit in the Druz Toolz slide hammer, both Druz Toolz carbon slide hammers, the econo slider, and the Tiddy Tab slider. It fits in many other slide hammers but sometimes requires sanding of the nut or changing the nut to a different size. The lock hole and locking nut keep you from having to permanently or semi-permanently affix your cold glue tab to a dedicated slide hammer. -No chasing a puck across the shop after a cold glue pull.