This is a must-have accessory for the Mark 7® 1050 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 7® tablet interface. ALSO acts as a brass sensor - when enabled can stop the press when brass is not present in the decapping station.