AR-7 Double Cable Release for ISO thread

The AR-4 and AR-7 Double Cable Release and the AR-10 Cable Release provide the PB-6 with automatic diaphragm control, even for a lens in the reversed position. The AR-7 is a Double Cable Release for all cameras that use standard cable releases. The AR-7 provides the PB-6 with automatic diaphragm control between the camera and the bellows focusing attachment PB-6 release plug; even for a lens in the reversed position.