I cant find what that thing is called if at all there is a word for that. Does anyone know what it is? This is some sort of load lifting device. Slings go in between the plates and well, there is a description:
used together with rope or textile slings and serves for simplification of unslinging process of represents a frame with the mobile probe After installation of load on the place is done and sling is weakened of a sling, the probe is pulled out and load is released.
In Russian it is called literary "Smalles'(name of the inventor probably, but i couldn't find anythins on him) lock".