Features Extra Large Cnc: This Kit Will Extend The Y Axes of Your Cnc to Move 470 Mm And Travel 320 Mm, Easily Converting Your 3018 Cnc to A 3040cnc. Compatibility: This Engraver Extension Kit Is A Direct Upgrade to Most of The 3018 Series Cncs on The Market, Featuring An 8mm Screw And 10mm Guide Rail. Simple Installation: This Engraver Extension Kit Is Very Easy to Assemble And Requires Only One Hexagonal Screw to Complete The Upgrade. Cost Saving: No Need to Spend Money on Another Model of Engraving Machine, You Can Adjust The Engraving Machine For The Size of The Object to Be Engraved. Excellent Quality: This Engraving Machine Extension Kit Is Made of Aluminum Alloy And Brass, Which Is Resistant to Wear And Tear, Not Easy to Break, And Has A Long Service Life. Specification: Item Type: 3018 Pro Engraver Extension Kit Material: Aluminum Alloy, Brass Base: Approx. 450mm/17.7in T8 screw: Approx.470mm/18.5in 10mm Optical Axes: Approx.450mm/17.7in Package List: 2 x Base 2 x 10mm Optical Axes 1 x T8 Screw 2 x Limiters 2 x Screw Holder 1 x Knob 16 x Mounting Screw 1 x Bushing Package List 2 x Base 2 x 10mm Optical Axes 1 x T8 Screw 2 x Limiters 2 x Screw Holder 1 x Knob 16 x Mounting Screw 1 x Bushing