Two-Piece Reversible Jaws; Jaws are composed of top and bottom pieces; American Standard Tongue and Groove Style; ISO3442 Highly durable; Steel inner mechanisms are quench hardened to increase toughness A2-6 Short Taper Adapter; Comes with a finished backing plate ready to mount chuck to lathe spindle 9 13/16" Body Diameter; 3 1/8" Through-Hole Diameter; 0.2362" to 4.3307" Clamping Range; 3.5433" to 9.8425" External Clamping Range Includes: Lathe Chuck, Adapter Plate, Lathe Chuck Key, Mounting Bolt (3) Lathe Chuck With Adapter Plate Combo Set