OK here is what I got back from the manufacturer. Hopefully it will help someone else.

Thank you for your inquiry & thank you for your interest in our Adjust -A- Wings & Super spreader products.


The Maximum height of the medium wing (at its most narrow setting) is just under 7.5 inches (including the height of the hanging hooks !!


The Minimum height (when wing is set at its widest) is approx. 4.5 inches.. (aint noone lower than us ?)