Oneway Stronghold Chuck #3 Tower Jaws, Serrated are expertly machined to a depth of 1-1/4", providing exceptional gripping power and strength for large bowls and vases. These serrated #3 Tower Jaws increased depth, which allows for more when working on the back of your piece, making them i for detailed woodworking projects. While they have a narrower range than profiled jaws, they come at a more price point. The top of the internal profile features a dovetailed design without serrations, specifically crafted for non-marking situations where you want to preserve the tenon on the bottom of a bowl as a design feature. These jaws are for woodturners seeking a balance between grip strength and gentle handling of their workpieces. Spigot (external) measures 3-3/4" to 5" and recess (internal) measures 4-3/8" to 5". Model Number: 3600