Flimsy
I've bought two of these plus and both broke the same place i.e. tightening down on main cover over a 16mm cable. They certainly are NOT suitable for such cables or hefty conductor thickness i.e. 5/6mm sq.

One other thing that bothers me about Furutech is their phosphor bronze alloy as the base conductor. Phosphor bronze is one of the worst conductors out there and coating with gold or rhodium (also an awful conductor) is like putting lipstick on a pig.