1MODULAR DESIGN FOR EASY MODIFICATION: Linear rail guide kit need no firmware or wiring modification. Easy to upgrade, start printing immediately 2LONG SERVICE LIFE: Linear rail guide upgrade kit is made of high carbon cr steel, possess strong wear resistance, fluent movement, low noise, uniform force and more sturdy 3HIGH SPEED PRINTING: The linear with low friction motion characteristics reduce energy lose and mechanical wear, enabling 3D printers to print at higher speeds 4HIGH ACCURACY PRINTING: The linear guide rail with high rigidity and high stability, which can maintain more excellent accuracy during motion, reduce printing vibration and inprove printing quality 5APPLICABLE MODEL: This 3D printer linear guide rail kit is compatible with for Neptune 3 Plus X axes and for Neptune 4 Plus X axes, meet can be used 1 x Guide rail 4 x Slider 1 Packof Screw Accessories 1 x Accessory