All our brackets come with a lifetime warranty.
As the table reveals the 6″ chimney bracket has stand off of 2.5″, and the 8″ mitre has a stand off of 4.5″
We would normally only recommend the 6″ chimney bracket for 3ft poles or for installs with small aerials (e.g. Yagi10K or FM/DAB single element aerials).
The 6″ bracket requires modifying if it is to accept 2″ V bolts.