This unit in natural finish anodised aluminium is a telescopic mast suitable for TV and other antennas. It will extend to 1.5 metres in 3 sections. The top section is 27mm dia., which is compatible with almost all TV antenna mounting hardware. The bottom section is 36mm dia., which would easily be accommodated by U-bolt or other clamping hardware (not supplied). The top section has a sturdy cap and features a slot, which enables you to neatly thread the coax lead down through the mast.