Star 430SWL and 430K Vista New OEM supplier, superb clamping power measured at 45Nm tightening with rotation. Motion-Lok technology.. Replacement rotor autochuck mechanism with "motion activation" technology. Under rotation grip force increases >45Nm. The spindle housing has been further improved by hardening the steel to withstand numerous rebuilds and overhauls. Each rotor combination CNC balanced assembly is serialized on the bur side for post installation readability and carries a 9-month warranty. Autochuck mechanism purchased separately carries a limited 4 month warranty. We suggest always replacing the CNC Balanced Assembly together as a whole.