uxcell Slide in T-Nut, M5 Threaded for 3030 Series Aluminum Extrusions Profile, Pack of 20: Amazon.com: Industrial & Scientific
Amazon.com: Odinest T Nuts Tee Sliding Slot Nuts 20 Series M3 Threaded Slide in Pre-Assembly for 20x20 Aluminum Extrusions Frame with Profile 2020 Sereis 6mm Slot for CNC Router Build Rail 3D