The added hole is there to give the rope an alternate path that increases friction, so you can add braking power compared to a simpler, single-path setup.
Think of it like adding a built-in “friction station” to the carabiner: instead of the rope only running through your device and a standard locker, you can route the rope so it wraps an additional feature point. That extra wrap is what boosts control when you’re managing speed on a single-rope descent or when you’re lowering someone.
A great real-world example is the Petzl Freino Carabiner + Friction Spur. It’s a locking carabiner that can be used like a normal twist-lock, or you can loop the rope around its friction spur once your rappel is rigged (or once you’re set to lower). The result is the ability to add or adjust braking power without rebuilding your whole system.
Compared to a simpler carabiner approach, that “extra hole/point” doesn’t magically change your device—it changes how the rope runs through the system. More friction generally means a calmer, more manageable descent, especially when you want to fine-tune speed rather than fight it.
When a carabiner gives you an optional friction point, you’re buying control you can choose. With the Petzl Freino Carabiner + Friction Spur, you can run it as a standard twist-locking carabiner, then add friction by looping the rope around the spur when you want more braking power. That flexibility is the whole point: one locker, two “modes.”
The same concept that helps on a single-rope descent can also help during a lower. The Freino’s friction spur can assist belayers by increasing braking when lowering a partner—useful when you want smoother speed management without constantly white-knuckling the rope.
If you don’t need the added friction point, a classic pear-shaped locker can keep things clean and rope-friendly. The Petzl Attache Bar Carabiner uses a round-stock basket designed to create a smooth surface for the rope to run over, which can make belaying feel smoother with devices like the VERSO or REVERSO, or when using a Munter hitch. Add the removable BAR and it becomes unidirectional—helping keep the carabiner oriented to load the major axis during belays or glacier travel.
If you’re deciding whether that added hole/feature is worth it, start with how often you want to change friction without re-rigging. A braking-style carabiner is about optionality—run it normally, then add friction when conditions (or comfort) call for it.
Look at the Petzl Freino Carabiner + Friction Spur if your priority is being able to add or adjust braking power during single-rope descents, or to assist with lowering. The key is that you can use it with or without the friction spur, so you’re not locked into one feel.
If your bigger concern is keeping the carabiner oriented correctly during belays or glacier travel, the Petzl Attache Bar Carabiner is built to become unidirectional with its removable BAR—helping it stay loaded on the major axis. Its round-stock basket is also designed for smooth rope running with common belay devices or a Munter hitch.
If you’re attaching devices and counting grams, the Petzl Sm’D Triact Locking Carabiner is a compact D-shaped aluminum option recommended for work at height to keep weight down, and its shape is especially suited to attaching devices. It comes in different locking system options depending on the version.
Backcountry is for the folks who obsess over the small details—because the small details are what make systems feel smooth, controlled, and confidence-inspiring. That’s exactly what this “extra hole for braking” conversation is about: not hype, just how rope routing changes the way your setup handles.
Want to talk through which option fits your descent and lowering style? Our Gearhead® Expert crew is here for the nerdy questions and the practical ones—like when adjustable friction is a game-changer, and when a simpler, smoother-running locker is the move.
Bottom line: choose the tool that matches how you actually climb—then go put it to work.