If you have an eShapeoko with NEMA 17 motors on the X and Y axis, and would like to upgrade to NEMA 23 motors, this is the kit you need. It includes M5 fasteners and spacers, 6.35 mm bore pulleys, and a pair of belt-on-the-side belt anchors for the X axis. It is exactly what you'd get with an eShapeoko if you ordered the NEMA 23 hardware for the X and Y axes: Pack 3 T and 2 × EM-LBA1 belt anchor from Pack 6 S. Please see the packing lists: with MXL pulleys, and with GT2 pulleys (PDF). This upgrade supports belt configuration D for the Y axis, and D, E and F for the X axis (see the assembly instructions for the belt configurations). A separate add-on kit is available that supports the E and F configurations for the Y axis (but you still need this kit).