These 60mm Shark Jaws been superseded by the current 55mm Shark Jaws. These Shark Jaws have serrated inner and outer jaw surfaces. These extended jaws provide an aggressive hold.  they hold cylinder spigots much more safely than standard jaws.  They are much easier and provide vastly better grip than traditional jaws used to turn long work pieces. The inside diameter of the serrations is 45mm at a perfect circle, the outside diameter is 60mm & the depth is 53mm. These Jaws also have a nickle plated finish.