It comes with 4 insert rings with different apertures and some mounting screws. Please note that some woodworking engraving machines with special mounting hole spacing can be measured according to the size drawing. When installing, you only need to punch holes in the corresponding screw installation position to install the screws between the plate and . Features - Color: Red. - Material: Aluminum alloy. - Size: 23.50X12.00X0.80cm/9.24X4.72X0.31inch. - It has multiple mounting screw holes, making the installation more secure. The screw holes are finely processed, and the threads are clear. - It is an essential tool for most carpenters and household project DIY enthusiasts. - It can be used for carpentry grooving, trimming, furniture processing, DIY production, etc. - Easy to operate,save effort and expand the use of the trimming machine at the same time. - Adopted of premium and safe aluminum alloy with stable performance for . Package list: 1 x Set of Engraving machine flipping board