Pickup Box Utility Rails are constructed of bright anodized aluminum and enable for infinitely adjustable cago box tie-down possibilities. Utility Rails run the length of the bed sides. The middle channel of the Utility Rails are designed for attachment of a Sliding Toolbox and/or Sliding Bed Divider. Sport Utility Bars can be added that include a T-Slot mounting feature for adding Bed Basket, Ski Carrier or Bike Carriers. Utility Rails include 4 tie-down Cleats that unlock with a pull-and-twist action and can be locked in place every 3 1/4". Cleats are rated at 320 lbs. each. Ram 1500 5.7' Bed Fits conventional beds. Does NOT fit RamBox. This item is large and CANNOT ship via USPS.