I did ask that very question of the very helpful Dr Harrison, the insight rods were based on the chimera blank, the 12’ RB had a 1.5 lb tc quiver top, and a 1.75 & 2.0 lb hollow top.
The 1.75 & 2.0 tops were also available as stand alone rods
There was also a SU version which was 2.25lb which were superb rods for the tidal Trent .
As mentioned earlier there was also a “flood” rod but I found it far too rigid & more suited to the beach!!!
I do speak with experience as I have a pair of multi specs, a pair of SU’s and a couple of stand alone rods.
It is also worth noting that late run rods are not made with Harrison blanks but a cheaper substitute