Good question! Choking knots can reduce the MBS up to 50% so I assume that's what they're factoring. I was under the impression that the WLL was 10% of the MBS though.I've been trying to do some research and figure out the MBS and safety factor of WLL of the Chisolm crane slings. Treestuff lists the WLL as 8,400lbs for a choker. Is that a 5:1 safety margin? By "choker", does that mean just tying of the working end with a cow hitch or some similar hitch to the pick? Anybody have pictures of the tags on these slings?