Flex ducting magnetic coupler

Print two of these to join a flex duct through a screen!
Designed for 4" ducting like this:
http://smile.amazon.com/FO450-5-ply-Supurr-Flex-Aluminum-Ducting/dp/B00009W3H2/ref=sr_1_2?ie=UTF8&qid=1412923160&sr=8-2&keywords=flex+ducting
Using magnets like these:
http://smile.amazon.com/gp/product/B001ANVAHI/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1
And hose clamps like these:
http://smile.amazon.com/Spectre-9704-Hose-Clamps-Pair/dp/B004AJ352W/ref=sr_1_2?ie=UTF8&qid=1412924144&sr=8-2&k