Spotted this on Intelligent Armour’s website.
It’s a curious design, but works simply.
Here’s the description:
Idea for military and Special Forces use, the Austrialpin fifty fifty autolock carabiner features two identical compartments that open alternately with a sliding spring-loaded clip and lock automatically as soon as one loses the hold of the clips.
Needless to say, because of this carabiner’s simplicity and because I’m not going to use it as a belay, this overview is quite short.
Any carabiner could do the job of this one, for what I want it for (Airsoft). But none do it in such a cool way.