In reply to a post by fiddler:

I was wondering if the smaller tube was rubberised and expanded to accommodate the mini-tubes.

Na, I don't think so, we have had our fibre tubing up our pole since 2011 I think only has 1 fibre cable in it at the moment and ours is larger in diameter and our can support I think 12 fibre strands, so yours may only be 7 to 9 stands maybe, unless they are smaller now.

Funny enough the thinner fibre cable that is used to daisy chain between Fibre DP's can have ~40 to ~90 or so strands in.

Paul