12-Inch Jorgensen ISD-3 Bar Clamp. The first bar clamp to expand by joining two clamps together with no tools or added accessories needed. The patented head design allows any two Jorgensen ISD-3 Bar Clamps to be joined together for greater clamping capacity. By quickly flipping the head 900 you join two clamps together and also increase total clamping capacity by 6-Inch over the original two clamps. Example: Two 12-Inch Bar Clamps joined together will give you one clamp with an 30-Inch capacity. With every two clamps you buy, it's like getting a third, larger clamp for free. Features also include 76% More Clamping force than our competition, new quick release knob for fast, easy changeovers, and dual durometer handles for a comfortable grip. The Jorgensen ISD-3 Bar Clamp head can also be reversed for spreader function.