Features: Brand new and high quality Material: Made from steel nickel-plated and aluminum, durable, corrosion-resistant, high strength and hardness. Widely Used: Used with V-Shape aluminum extrusion and V-wheels to create linear motion systems. Helping your 3d printer work better. Easy to Use: Hexagonal eccentric column allows up to 0.79mm of adjustment with a 10mm wrench. Package Contents: 10pcs hexagonal eccentric posts, 20pcs round isolation column, the quantity is enough for you more choices. Portability: This product is small in size and light in weight, which is very convenient to carry around. Specifications: Material:Metal Height:Approx.8mm/0.31inch 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: 10Pcs Eccentric Column 20Pcs Round Isolation Column 1Pcs Wrench