The CNC Shark HD Dust Boot is specifically designed for use with the Next Wave Automation CNC Shark HD. Constructed of a durable polymer composite, the flexible brushes on the boot conform to the surface being routed. The brush plate is held securely to the mounting plate of the dust boot with strategically placed magnets, so the brushes easily snap on and off to facilitate fast and easy bit changes. The 2-1/4"-diameter hole is the perfect size for dust extraction hose. Requires 2-1/2" Fitting (128685 or 153516) and 2-1/2" Hose, both sold separately. Next Wave Automation also recommends a Dust Collection Grounding Kit (812502).