Stoptech 2PC AEROROTOR and HAT NIS 324x30 LEFT DR

This part is identified as a Stoptech 2-Piece Aero Brake Rotor and Hat, drilled. Some descriptions also mentioned it as "AeroRotor 2-Piece Black Hat No Rotor Coating Drilled Front Left". These rotors are part of the AeroRotor series, which are typically high-performance brake rotors designed for improved cooling and lightweight performance. It is a 2-piece design, which typically involves a separate hat (center part) and rotor ring, allowing for better heat management and often lighter weight. It is also explicitly "drilled," referring to holes drilled into the rotor surface for improved cooling and to vent gasses.