This indexable bracket is used with the REV 15mm Extrusion System to create an adjustable shaft support. Both brackets have a sawtooth pattern which fit together and can be adjusted in 1mm increment. The larger bracket in this set has a 9mm center hole surrounded by a ring of six M3 clearance holes to use with REV Robotics Plastic Bearings to support a shaft. The smaller bracket in this set has alignment ribs on one side which are designed to seat the bracket into the extrusion channel increasing joint alignment, strength, and rigidity.