The present invention provides a reversible end assembly for use with cargo decking beams. The end assembly comprises a body formed from C-shaped plates coupled back-to-back that is slideably disposed within the end of a decking beam. Identical latch mechanisms at both ends of the body allow the end assembly to be reversibly mounted within the beam. Each latch mechanism includes an end tab formed from the plates that fits into openings (either A or E slots) in a mounting track. A retaining lip on the bottom engages the openings and a notch in the top provides room for the lip to be inserted and lifted out of the openings. An internal swivel latch fills the space left by the notch when in a closed position to prevent the retaining lip from lifting out of the openings.