Mammut Smart HMS Locking Carabiner for Sale, Reviews, Deals and Guides

It's a belay biner, with an extra safety feature with the clip that keeps the screw locked down and prevents cross loading. Honestly, more than I wanted to deal with as an experienced climber, but this would be very good for beginners or groups!

To be honest, this is not my favorite carabiner around. I liked the idea of it, but in practice I find it quite annoying. I picked this up to go along with my Smart 2.0 belay device. It seems pretty structurally sound and does prevent cross loading the carabiner, however there are other biners on the market that are more user friendly. I hate that you have to have the biner entirely locked to have the block clipped to the gate and there is no easy way to clip or unclip this quickly. So it's a hassle to clip this to anything since the block then swings free and snags on stuff unless this is locked. It's not a very streamlined design and I only use this climbing indoors because it annoys me clipping it to my harness with the block swinging loose.

Love the thick spine and width of the Crag Smart HMS, but the safety gate design is just too cumbersome for me. It's effective for preventing crossloading and absolutely bombproof in terms of safety, yeah. But you can't close the safety gate unless the carabiner is fully locked, even if you just have it clipped on your harness/gear sling unlocked for storage (while climbing as a second, for example), meaning the obnoxious plastic arm sticks out. Perhaps it's a petty qualm to have, but it's just enough to annoy me. I prefer the Edelrid HMS Strike Slider or Bulletproof Screw FG Locking Carabiner.

I do not usually have a problem of cross loading but knowing I can belay without the worry of it is really nice! I am a big fan of knowing you can only unlock it by taking off the safety gate as well. I recommend this as a dedicated belay carabiner.

Helps keep good orientation. Light, simple, secure. It's a screw-gate under the arm, and the arm only swings into place if the gate is fully closed and screwed so it's a good backup to possible loosening (can't loosen if arm is closed), and you can't use it unless it's screwed shut...