Jadeshay C3/4 CNC Extension Rod Milling Holder, Metal Straight Shank Spring Chuck Collet for Deep Hole Precision Processing Efficiency

AAAAAAAAAAAA+++++++++++++++

I bought it with intent to check and return if quality is not good - it is great that Amazon accepts the returns. I installed it in the mill, and surprise - I measured +/-0.005 millimeter (+/-0.0002mil) total runout (Mill+R8 Collet+ER20 collet) - which is sufficient for most tasks.I wish that the vendor could specify the runout - did I get one as a luck or the accuracy/runout are consistent and guaranteed?