This is a drop in replacement for the Vert carriage to arm effector bracket with 45 degree holes to screw in M3 screws on steel balls. This will allow you to add Magnetic arms to Steve Grabers' excellently designed Cerberus Delta printer found here: http://grabercars.github.io/Cerberus by just printing 3 very small replacement parts.Print relatively solid. Drill/Ream the holes. Tap with an M3. Secure to carriage with an M3 in the center (20-25mm). Screw in the balls gently (make sure the holes are well tapped).