Braces to hold the dancer so the 5015/Fan duct can't move sideways.
Heatset version can use 4.7 or 5.0OD heatsets and 4mm Long. 6mm works but stick out towards the Extruder motor.
Heatset version can be used with the stock bolts.
Hexnut version uses M3 hexnut but does require a 10mm Ultra flat head bolt.
Hexnut Frictionfit uses a M3 hexnut on the stock 8mm Ultra Flat head bolt and slides over the nut.