Urethane Cutting Knife 24" QS359 is 24" long and is the length of most urethane cutting knives. The QS358 was designed for the extra-long dashes found in vehicles today. Measuring a full 24" long and only 1/4" thick, the QS359 can reach the corners of the windshield with ease. Our heavy-duty knives have all replaceable parts and a Phillips screw so you can secure the blade tightly without stripping the screw. Both knives come with our unique “hide-a-blade” design that allows you to store an extra blade in the handle. Made of high quality, lightweight aluminum with a steel retaining block for the blade. Replacement retaining blocks and screws are available.