Cepco Tools Universal Joist Gripper Attachment, #BW-9 The Universal Gripper is a two-piece adjustable attachment for the Cepco BoWrench, that allows you to grab onto a single joist or double joist. With a simple thumbscrew for fine adjustment of the grippers width, spanning 1.5 to 4.875, this attachment is highly adaptable and will allow you to easily conquer any job alone. Get the most from your standard BoWrench with the Universal Adjustable Gripper. This is the same gripper that comes standard on the Universal BoWrench and features a thumb screw which adjusts the gripper to accommodate larger joists. Time Saving Construction Tools for professionals & diy'ers. Cepco Tool Company is dedicated to providing customers with products of real value.