FCT Tower Arm Size?

[Luke]

Does anyone know what size the bar below the Flight Clips on a FCT tower are?

I ordered an Nvert board rack to place on the bar below the Flight Clips and they sent me the incorrect size clamp. The clamps I have appear to be 2" clamps and are slightly too large. I keep forgetting to take a tape measure out with me when I go.

Thanks

[IceyTys]

Bump!! I have a 2016 G21 and I need to buy some tube clamps.....I think the bars below the speakers are 2.5" can anyone confirm???