Mark B.wrote a review of DMM Belay Master 2 Keylock Screw Gate on January 5, 2012
Ohh the internal debate - 4 stars or 5 stars???? Let me make it clear I absolutely love this biner. I love the fact that you cannot cross load it, I love the fact that the plastic clip won't shut unless the screwgate is done up, I love its simplicity and I love the smoothest action you can find on any screwgate commercially made. (DMM do make amazing screwgates - FACT!!)
So why 4 stars? The only reason I gave it four stars is because the plastic clip can be detached from the biner and lost. Over the last three or so years that I've been using mine only once has the plastic clip been twisted off the biner when I had it attached to one of my gear loops (maybe I should learn to always clip it fully closed but when I'm not belaying I sometimes leave it simply closed on a gear loop). Luckily, at the time it fell, not only did I notice it had been knocked off but also it fell somewhere where I could pick it up and re-attach it, ie it didn't fall 200feet down a rock face. I have also heard about one guy who had his plastic clip nicked in Camp 4 - not good! I guess the reason DMM manufacture it like this is so that you can take the clip off and use it like a normal biner but I never need that, I have a bunch of Shadows for that. Also when you compare it to a Girdlock, you cant take the metal piece off that - there's no 'semi' dual use for that biner, so I would say you could make the plastic clip a more permanent feature.
Like I said though - this is an awesome biner and I wouldn't trade mine in for any other (Gridlock or anything). I'm currently thinking about getting one (two?) more to use with a Silent Partner.