Whiteside Screw Type Helix Mortise Cutter Arbor, 1/2 in. SH x 1/4-28 TH is designed for use with Whiteside's Helix Mortise Cutters, which are sold separately. This versatile arbor can be used in both handheld and machine routers, making it a flexible choice for various woodworking tasks. It features a 1/4-28 end thread size and a 1/2 inch shank size, ensuring compatibility with a range of router setups. Manufactured by Whiteside Machine Company in Claremont, North Carolina, this arbor is crafted to meet high standards of quality and durability. The overall length of the arbor is 1-3/4 inches, providing the right balance for precision and control in mortise cutting applications. Model Number: HMA-1/2