ITEM NAME:2Pcs 12mm SC12UU Linear Motion Ball Bearing Slider Slide Bushing Replacemen M1P6 2Pcs 12mm SC12UU Linear Motion Ball Bearing Slider Slide Bushing Replacemen M1P6 Aluminum ball bearing box sliding unit with sealed ball bearings, easy to install by bolt on a working platform, and to move through the design of compact Aluminum, SBR, TBR series linear guide side railalternatives, low cost, for linear motion precision is not very high occasions. Ball in the cage loop to run a smooth ball guide surface to ensure even if high-speed operation, low noise. 100% Brand New and High Quality Model: SC12UU Shaft ID:12mm Shaft OD:21mm Quantity: 2pcs Weight:191g Material:?metal Package Included: 2 x SC12UU Ball Bearing Slide Bushing Note:Light shooting and different displays may cause the color of the item in the picture a little different from the real thing.The measurement allowed error is +/-1-3 cm.