Dimensions: length is 27cm/10.63"; width is 13cm/5.12"; height is 14cm/5.51", needle seat is 80mm/3.15". The inner diameter of the suction port is 9.1cm/3.58in; outer diameter is 9.7cm/3.82inch, so it only fits 4inch dust collection tube. High Quality Material: Our products are made of high quality nylon high quality. Durable, not easy to wear, good toughness. It can be used longer. Easy to assemble and install: The shoe cover shell is pre-assembled and can be installed and used as long as the brush is attached. Push-pull buckle design, non-slip, firmer. Application: This NL330 CNC dust shoe can be used in advertising engraving machine, woodworking engraving machine, machine with pressing rollers to remove wood shavings and dust on the workbench.