DMM makes some of the highest-quality and best climbing hardware—period. And the DMM Ceros gets my vote for the best locking carabiner to use with a GriGri. Before reading on, check out the Evening Sends Guide to Choosing a Belay Device.
DMM Ceros: Function and Form
The DMM Ceros is virtually impossible to cross load, which adds a higher degree of security while belaying. An ingenious little protrusion on the carabiner’s spine prevents the GriGri from sliding down onto the spine, and the mini gate at the base of the carabiner keeps the Ceros from shifting once its clipped to your harness belay loop.
Getting it clipped to the belay loop is easier than other biners of this kind. Just clip the Ceros to the belay loop then pull it, and it’ll automatically clip itself to the belay loop.
Ease of Operation
Compared to other carabiners of this design, I find the DMM Ceros the easiest to operate one-handed. There are three types of gates you can get with the Ceros—one is a manual screw-gate lock, and then there are two auto-locking gates, one requiring an additional action to open. I prefer the red QuickLock gate because it’s the easiest to open and shut one-handed.
Obviously this is a single use item that seems to be meant to work with an assisted-braking belay device like the GriGri. But for what it is, it’s worth having.
I discovered a serious problem with using a Ceros and a Grigri together, The lever on the Grigri can easily be pushed into the clip on the Ceros, capturing it in the full open position. This is possible while using the Grigri in the recommended way. The “horn” on the Ceros can actually help line the lever line up with the clip, making it even easier to clip it. I happened to watch a video of a guy from DMM talking about the advantages of the Ceros as a belay carabiner for the Grigri, so apparently they aren’t aware of this.