The Vevor 4040 T-slot aluminum extrusion linear rail set includes four 39.37" rails designed for precise, customizable builds. Made from 6063-T5 aluminum alloy with an anodized surface, these rails offer corrosion resistance and long-term durability. Their smooth, burr-free finish helps reduce friction for reliable operation in CNC, 3D printer, laser engraving, and automation projects. The side groove design supports M6 and M8 T-slot nuts for flexible assembly. Lightweight construction makes them easy to cut, handle, and integrate into DIY or professional setups.