The 12mm REX™ Shaft (Aluminum, 43mm Length) is designed to provide structural support by connecting components such as the 1120 Series U-Channel. Its length aligns with the channel's width, allowing secure fastening with screws to unify the sides. Additionally, it can be utilized between plates or 1121 Series Low-Side U-Channel pieces, enhancing the strength of the assembly due to its substantial footprint.