Jacobs Chuck. Unique design on the standard instrument for introducing bone pins. An open slot cut into the handle permits visibility of the pin resting in the chuck, saving time by allowing the surgeon to check pin depth without having to remove the chuck. The stainless steel Jacobs chuck accepts K-wires as small as 0.9mm and pins as large as 6mm. The handle and extension piece are lightweight, blue anodised aluminium alloy. Key and extension piece included in set (also sold separately).