Abstract: An apparatus for immovably attaching or holding objects to a vehicle, trailer, platform or the like. The apparatus comprises at least two rails. Each rail is fixed and attached to the vehicle or the like, each rail having a channel that runs most of or all the length of the rail. The apparatus further includes at least one attachment device, the attachment device received by the channel of one of the rails, two projections of the rail constraining the attachment device to slide within the rail, whereby the attachment device attaches or secures an object to the rail. The attachment device is made and configured to slide within the one rail, and also configured to be immovably fixed at a desired position within the one rail by operating a locking mechanism that is part of the attachment device. In a preferred embodiment, the locking mechanism comprises cams that wedge against the projections of the rail.