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The Black Diamond Oz is our Top Pick for Lightweight award winner. It's not the absolute lightest model on the market — that distinction goes to the CAMP Nano 22 Carabiner, our Top Pick for Ultralight — but the Oz hits the sweet spot between lightweight and usability. There is a wire hood that covers the notch for the wiregate, resulting in snag-free climbing, and while they are slightly smaller than a full-size carabiner, they are not so small as to be unusable. As the name suggests, they weigh only one ounce, and you'll barely notice them on your rack. This is a good entry point for those that are used to larger carabiners but looking to lighten up a bit, and you can purchase them in assorted colors for racking your cams. They also fit the wider slings on the BD Camalots better than most other carabiners. If you really want a full-size carabiner but don't mind a few extra grams, then our Editors' Choice winner, the Wild Country Helium, is our number one choice.
Product Recall: February 2016
In February of 2016, Black Diamond released a recall of Oz carabiners - 210230 and 381052. If you think you might own any recalled carabiners, read this safety recall notice to determine your next move.
Our Analysis and Test Results
The Black Diamond Oz carabiner is a hot-forged wiregate with a 22 mm gate opening. It weighs 28 grams or 1 ounce, hence the name. It currently retails individually in black, silver and orange, and as a six-color rack pack (grey, purple, green, red, yellow and blue) to match BD's .4 to 3 Camalots.
Ease of Unclipping
In our original carabiner review years ago, the Oz did not score well in this category. The combination of small size and exposed notch in the gate made unclipping this product a chore. Since then, Black Diamond has added a stainless steel wire hood over its nose, and the notch is no longer exposed. This has made a big difference in its usability.
It's still a little smaller than a full-size option like the Wild Country Helium, but it's larger and more user-friendly than the CAMP Nano 22. Our testers found that unclipping the Black Diamond Oz was a little more challenging than unclipping some of the full-size competitors in our review, but it was significantly easier than unclipping the "keychain" size ones. The hood on the notch also helps prevent the gate from accidentally opening when pushed against the rock.
Ease of Clipping
The gate tension on this carabiner feels a little stiffer than some of the other products we tested. You have to push really hard on the gate to get it to fully open. While our testers found that this made clipping it a little bit harder than the similar sized Mad Rock Ultra Light Wire, there are advantages to a stiffer gate.
When the gates are jammed up against each other on a rack or harness, they can cross-clip each other, particularly if the gate tension is weaker. This happened to several of our testers with the CAMP Photon Wire, which was also the easiest product to clip.
Ease of Handling
This carabiner handles reasonably well, though when we tried it with gloves on, our testers did find it more challenging to operate than a full-size model like the CAMP Photon Wire.
If you plan to use your gear in cold conditions on a regular basis, you might want to consider a larger carabiner. On the other hand, it does have a very narrow profile, which is nice if you like to rack on your harness but don't want your gear loops to be overstuffed.
How Many Ropes Fit
This model did reasonably well on our three-rope test. We could still open the gate after clipping three loops of 10 mm rope in it. However, it was pretty crowded due to the smaller size of the carabiner. It has a 22 mm gate opening, and the CAMP Nano has a 21 mm.
You wouldn't think that a single millimeter would make that much difference, but apparently, it does. Both the Nano and the Metolius FS Mini II were difficult if not impossible to open with the three loops clipped, but the Oz and Mad Rock Ultra Light (also 22 mm) could still open, if barely. This product also worked well with our 7.8 mm twin ropes.
Rope Pull Smoothness
The rope bearing surface on this carabiner is a little narrower than the Petzl Ange L, and our testers could tell the difference in the smoothness of pull between them.
This metric is something to consider when building a top-rope anchor. If you have mainly smaller models on your rack, bring along a few beefier ones like the Ange L to use up top. It will be easier on the belayer, and easier on the rope. The latest version of this carabiner (redesigned in 2016) does have a larger rope-bearing surface than the previous version though.
At 28 grams, this piece of gear is well within the lightweight zone. It's considerably lighter than most sport climbing specific carabiners, and less than half the weight of an old school oval. Still using ovals on your big wall rack? This might make you reconsider - if you took 40 Ozs up a wall instead of 40 Ovals, you'd shave three pounds off your rack!
As mentioned earlier, there are lighter carabiners out there. The CAMP Nano 22 is only 22 grams and the Metolius FS Mini II weighs 25 grams. So you could go lighter and save even more weight. If you were carrying 20 Oz models, say on a double set of gear, you'd be adding four ounces over the Nano 22s. If you are truly looking for the lightest option possible, then go with the Nanos. In most instances though, our reviewers felt that the extra ease of use of the Oz was well worth those 4 ounces.
The Oz is great for a variety of uses. Black Diamond now makes it in a set of six different colors to match with your gear, which makes selecting the right piece and re-racking at the end of a pitch significantly easier. It's also a good choice for racking your nuts because there is no notch for the wires to snag on. While wiregates are preferred for ice climbing, this carabiner is a little on the small side for using with gloves on. When it comes to big walls, if you climb with fingerless gloves these still handle ok, and you'll be motivated to figure it out quickly once you realize how much weight you are saving with them. They are also available in a quickdraw and alpine draw setup, which won our Top Pick for Lightweight as well in our quickdraw review.
These carabiners retail for $10 individually, or $60 for the six-pack. Unfortunately, you can't buy the racking colors individually at this time (except as seconds), so if you want a red or green or blue one, you'll have to buy the entire rack pack. If $10 a carabiner seems a little steep for you, the Mad Rock Ultra Light is a similar size and several dollars less a unit (only $6), but it still has an exposed notch and does not come in racking colors. The Trango Phase retails for $6 and comes in eight colors. There's always the old Black Diamond Neutrino as well, which is a good second choice if you are looking for something cheaper in assorted colors, but it too is heavier and has a notch in the gate.
Sometimes it's easy to get caught up in the goal for lighter and lighter gear and forget that the gear does not just sit on a scale looking smug but will actually get out onto a climb and need to be functional. The "keychain" carabiners seem like a good party trick ("Yes these really are full-strength…"), but when it comes to something you'd want to climb with, weight isn't the sole consideration. Black Diamond seems to have found the right mix of weight and usability with the Oz. They made it as light as they could while still keeping this product something you'd want to use on your cams and not just your nut tool. If you are looking for a carabiner that's lightweight and high-performing, our Top Pick award winner is the way to go.
GearLab is founded on the principle of honest, objective, reviews. Our experts test thousands of products each year using thoughtful test plans that bring out key performance differences between competing products. And, to assure complete independence, we buy all the products we test ourselves. No cherry-picked units sent by manufacturers. No sponsored content. No ads. Just real, honest, side-by-side testing and comparison.