Universal 1U/2U/3U/4U ball bearing 20" sliding rails, very thin Quantity in Basket:noneCode: KRI-USR20 Price:$65.00Shipping Weight: 10.00 pounds Quantity: 3-section Ball Bearing rails * Heavy duty 20" Ball Bearing sliding rails, NOT friction type. *Good for 1U, 2U, 3U, and 4U chassis(but NOT NORCO chassis).