Droll Yankees offers this Incredible Adjustable Deck Clamp & Hanger that fits any size flat deck rail. The 16" hanger arm has 360 degree positioning and a locking hook. The 46" pole is adjustable to just the right height and you can add extra height in 46" increments with the SPS Single Pole Section (sold separately)

Construction: Galvanized and powder coated steel
Dimensions: 46" length with 16" arm hanger and 1" outer diameter
Warranty: Lifetime
Made in the USA