What size pole should I use for Ironridge Side of Pole mount?

Thank you for the question:

• UNI-SP/01 to UNI-SP/02 use 2" to 4.5" schedule 40 pipe.
• UNI-SP/02A and UNI-SP/02X use 3" to 4.5" schedule 40 pipe,
• The UNI-SP/03 can support either 4" or 4.5" schedule 40 pipe. 

Also, please check this article about Ironridge Pole Mounts:

https://www.greentechrenewables.com/resource/ironridge-pole-mount-sizing-and-installation