Uniquely designed to smoothly plunge through urethane corner beads, the GT Tools® 3" x 10" Round standard sheath blade is made of high carbon spring steel for maximum durability. This blades are designed to work with GT.357, GT.38 Special, GT.44, and GT.45 reciprocating auto glass cut out tools, The GT Tools® Quarter Cutter™, the GT Tools® Shorter Cutter™, as well as other industry recognized reciprocating tools.