Established in 1987, M-3 has been an innovator in the cargo, enclosed trailer and the RV industries. Some of the product offerings include: Ramp Door Spring Systems, HVAC Ductwork, Exterior Trailer Lighting, Aluminum Barlocks, RV Bunk Ladders, RV Slide Out, Battery Trays, Cabinet Slide Out Systems, In-Floor Trailer Storage Boxes, SecurityPlus Trailer Door Locking Systems and Various Stamped Brackets. We can also design and build your custom parts.