The 3-inch long steel replacement blade attaches to the cast aluminum Hubbard brick jointer (Kraft tool no.bl280). The replacement blade extends the use of and longevity of the tool. The blade creates a 5/8-inch concave joint on brick and block. Rotating the blade around the handle helps to evenly distribute the wear and extends the life of the product. The polished blade creates a smooth groove in the mortar every time. More sizes are available. This unique tool was designed by a bricklayer with 60 years experience. Proudly made in the USA. Kraft tool co. Has been an American manufacturer of quality hand tools for the concrete, masonry, asphalt, plaster, drywall, tile, floor covering, and leveling trades for over 30 years.