Presentation Image for Truss Kit C36-104 Aluminum Lighting Truss. 4 Chord Box Truss. 20’x20′ by EDT Exhibit and Display Truss and LDS Light Design Systems. This is the C21-104 but has an additional truss beam in the center for hanging lights and truss accessories. Dont settle for used stage truss when you can buy lightweight aluminum truss instead for around the same cost.