Sorry that wasn't what you asked. I run with the Airforce 1, that works off of my Palazzo air brakes to a piston/cable armature hidden and attached to my toad brake pedal. It appears that the DUO works off of vaccume. Nonetheless, SMI has great products and great support and customer service.......to me it all boils down to preference.
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2016 Thor Palazzo 33.2
14 Honda CRV, Roadmaster Tow Bar, Air Force 1
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