The M3 M4 M5 20 series Aluminum Extrusion T-nut Square Solid Slide in Nut is a high-quality fastener designed for aluminium profiles. This t-nuts are perfect for securely holding aluminium extrusions in place. These t-nuts are ideal for use in a range of industrial and office settings. With a simple and reliable design, these t-nuts provide a secure and stable connection for your aluminium profile needs.