New improved design makes it much easier to compress tough mainsprings with two rotating, adjustable jaws that screw down securely. Adapts to angle of spring, spreads compression evenly over the entire spring area and is perfect for installing “V” springs in shotguns and muzzleloaders. Wide turnkey allows you to use your thumb and index finger to really squeeze tough springs down without the need for makeshift tools. SPECS: Steel, in-the-white. Made in U.S.A.