Features: Brand new and high quality Made of high-quality metal material, durable, firm and has a long service life. Dual Y axis structure, smooth and stable operation, reduce the leveling difficulty and leveling-time. Easy and simple to operate and use, no other tools needed. To upgraded the 3D printer into dual Y axis type, greatly improve the stability of the printer. There are stoppers on each side of the linear rail, it can prevent the carriage block from falling out. Specifications: Material:Metal Type:With Guide Rail/Without Guide Rail Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1 Set Guide Rail