The Attache is a proven locker that I have used for years. It opens reliably and stays closed and locked when you want it to. It doesn't need to be overtightened, but if it is can be undone with some tension while opening. Like all crabs it will get challenging to open in icy conditions when the temps are near freezing or near freezing and get really cold when things are wet. I put mine inside my jacket to dry/warm it and it works. Or blow on it to heat it up and get it open. Strong this crab is. Heavy by todays standards, that is why I give it four stars instead of 5. Looking forward to Petzl's new carabiner line which will eventually come out and blow everyone away with the quality and innovation.

I carry one of these on my harness at all times, and it's great for a variety of purposes. I use it for belaying with smaller ropes (though I switch to a larger biner for big singles), and it is also quite good for general rigging (thanks to the snag-less gate). My main use for it is as a self-rescue biner, because it is small and compact enough to carry at all times (I also carry my prusik loops and chap-stick on it), but the basket is large enough to hold a Munter on twin 8mm cord (such as when constructing a load-releasing hitch out of a cordalette), which makes it very useful for belay escapes and knot passing. All in all, a very nice piece of kit, which gets 4 stars only because it is heavier than other comparable biners due to the large, rope-friendly bar stock it is constructed of.

I love this biner for setting up my belay stations and top ropes. It's pear shape accomodates the multiple strands of cordelet or webbing nicely. The red band on the screw gate gives a nice quick-glance saftey check.

This is a nice biner, but it is a little to tight with double strand 9.2mm static rope. I do like the roundness to the shape though.

The keylock locking gate is awesome, it never snags on anything. One quick glance and you can confirm it's locked.

For me, this is the gold (or blue) standard for belay carabiners. The screw mechanism is exceptionally smooth and solid feeling -- compare it to some others to see the difference. Like butter, it is. Snag-free keylock gate: check. The round profile feeds rope very smoothly. And, the red "idiot stripe" indicator gives a clear visual alert to ensure it's locked correctly. Why don't all locking 'biners have that?

I have used these carabiners for years and will continue for many more!
Make sure,especially in cold weather you do not over tighten the screw lock.

This is a great locking biner. Notch less, fairly lightweight and fairly inexpensive. Coming from Petzl all these attributes are a given, but the price is phenomenal from Petzl for sure. Buy this biner, and a few more for anchoring, crux pro, or even organizing your gear in your pack.

Great addition to your rack. The size and shape of this multi-purpose carabiner make it useful especially when connecting a belay device to your harness. Also great for employing the "Munter Hitch" when belaying with single ropes.

Best locker! Not to big, not to small, nice gate opening, smooth action. Perfection!

Great for those moments when a Large locking biner is not necessary. I am currently working on phasing out my old positrons with these for anchoring setups. Bomber feel in a smaller carabiner is a nice thing to have when most smaller biners just feel skimpy. For a little increase in weight, the dependable benefits make up for it. Safety indicator is a given.

There are a lot of HMS lockers on the market. This is one of the least expensive. It's simple and does the job. Why pay more?

When i first started top roping I bought 2 of these for the top for my rope to slide though. I love them! I have used some other black diamond lockers and they work well but these work and feel so much better. The lock feels so solid and so smooth to open or close. Overall a great locker

I use this for my belaying needs. I use it with the Trango Cinch and all my ATC style belay devices. The red is dead indicator is an added bonus!

This little beauty is great in a canyon. Non-bulky on the harness (thus slides through slots well), yet still HMS-ish shaped for tying a munter-mule or other contingency in a rappel. The keylock makes it easy to clip/unclip while a little bit weighted (while changing over, mid-rappel etc), and the red line makes an unlocked 'biner easy to spot from a distance. Plus, for its size, the gate clearance is pretty huge. However, it feels a bit small for my climbing style, but maybe I'm just used to larger locking carabiners.

One of my climbing instructors recommended these biners by name. The lock spins open and closed easily so that you can do it with one spin of the finger. This can be good or bad: if you're afraid rope friction might open it, it's a bad thing, however, I find it very convenient.

I love clean profile carabiners. It's so much more convinient at a crowded hanging belay to be able to remove a biner from whatever without it catching. These biners are light, strong, and simple too. Buy a couple of 'em or you'll wish that you had.

The Petzl Attache Locking Carabiner is easily one of my favorite biners. The lock opens and locks off easily, the gate is convenient and never sticks. Its the one biner that works exceptionally well with the petzl pirana, which is my favorite rappelling device. They aren't too heavy and are super reliable.

The shape of this biner, combined with the nice round dimensions make this biner soft on the rope and easy to use. Petzl also adds an additional red line around the gate to make it easy to tell whether you are locked or not.