Direct Metal Mastering PR-M in runouts: The additional letter M stands for Metalworker, currently unknown. Matrix / Runout: P12 MUTE 152 - A1 THE EXCHANGE DMM PR-M DMM A (Etched A side) Matrix / Runout: P 12 MUTE 152 - B1 JONZ DMM PR-M B (Etched B side)