thats what i though too....Haul yourself up the mast unassisted device??
Oh, and the black line with a ratchet hook is just a simple hardware store style tie-down. Also not recommended for climbing anything.This is a Harken Hoister, used to hoist things (kayaks, bikes, truck caps, keep tops, etc.) to a garage ceiling or similar.
It is most certainly not a system for climbing anything or supporting humans aloft, unless you like high risk of serious injury. The unrated plastic snap buckles, unknown webbing, and lightweight frame clutches should perhaps be avoided in climbing systems.