Use this W. Rose™ 3/4" x 7/8" Concave Jointer tool to make a protruding beaded masonry joints. Creates a consistent convex joint every time for a watertight seal popular in historical restoration. Each end makes a different size joint for versatility. One end makes a 3/4" joint, then flip it around for a 7/8" joint. Made from formed high quality steel for durability. The jointer is then sent through a unique heat-tempering process for hardness and long wear. The steel is then polished for a smooth, perfect joint every time. The shape of the tool provides knuckle clearance as you move along the joints. The overall length of the tool is 10-1/2" long.