Forgive me for I am konfuzed.
Is the LH valve bit a belated April Fool's joke?
If so, on one hand, it has reached the stage that I don't know whether to believe it or not whilst, on the other hand, the concept seems so outrageous that it might just be true. (Too many hands doing we know not what, perhaps).
If true, who uses LH valves and for what purpose?