Andrew, this one drove me crazy.. not only does it not fit properly, once you do jury rig it on, the cable release, when fired, makes the adapter slide around the lens preventing the shutter from firing! Very poor design, one of the only poor product I have bought with the Toyo name on it. My solution was buying a $15 right angle cable release extender. Just screw it in the cable release socket and then attach your cable release to the other side, it works flawlessly, so go get you money back and make your life easier and install one of these 90 Deg. angle calbe relase extenders.. they are available just about every camera store that sells LF. good luck...