Ubiquiti IsoStation Mounting Bracket is made of die-cast Aluminum and is very rugged. It has 3 axes of movement, horizontal around the pole it mounts to, vertical on a built-in hinge, and the radio can rotate 360 degrees.
The bolts to clamp the bracket to the pole are standard 13mm, similar to several others on Ubiquiti radios. It will fit up to a 75mm pipe (with larger bolts - the ones it comes with are long enough for something in the 50mm range).
You can point the radio in virtually any direction and rotate it to keep it level, even if the pole is not. The hinge is tightened with it's own 5mm cap screw, and should be rock solid once tightened - even loose it's a tight fit to make aligning it easier.
Use with the ISO-514, ISO-514AC, PS-5AC radios with any variant of Horn antenna.