The Matthews 10" Extendellini For Matthellini Center Jaw Clamp is an ingenious accessory that allows you to extend the grip of any Matthellini clamp by up to 10" (25.4 cm). Just remove the removable jaw from the Matthellini clamp, thread the end of the Extendellini into the end of the pin on the Matthellini, replace the jaw, and the reach of the jaw has increased by 10".