To use the Starrett DB2 Debris Collector, simply insert the arbor shank through the eyelet at the nylon base, press the rim of the cowl against the surface of the material being sawn and begin sawing. The flange of the cowl then forms a seal against the material being cut, collecting all dirt and debris inside the cowl. Suitable for TCT Fast Cutting Multipurpose and Bi-Metal Hole Saws up to and including 121mm (4.3/4in). Ref: UTTK7757