Optical DecapSense Sensor Features This is a must-have accessory for the Mark 7A(R) 650 Autodrive. The positive decap sensor uses optical recognition to determine if a spent primer is removed and if no spent primer falls the machine stops after the stroke making easy to remove the impacted case. Save yourself and save your machine. If you are processing or loading new brass simply disable the sensor from the Mark 7A(R) tablet interface. ALSO acts as a brass sensor - when enabled can stop the press when brass is not present in the decapping station. Optical DecapSense Sensor Specifications Decap sensor Brass sensor when enabled can stop the press when brass is not present in the decapping station. Reduces injuries and machine damage This is only available for users of the Mark 7 650 Autodrive.