Although the MC-20 can be used as a cable release it's button is submersed within the shaped controller. The MC-20 however is simply a large button, it may look crude but you can grab and use it without looking or fumbling. The button is press sensitive like the cameras shutter release so lightly pressing it activates AF and the metering system. You can use this release with ease in the cold and when wearing gloves. Compatible with F5 and D1h.