Bamboo Ferrules.
There are plenty of well-documented benefits of and all cane connection of rod sections. But what interested me most was the weight saving, which should allow a smoother and faster rod.
This one is a “Sleeve” type ferrule formed of another hexagonal section of cane made to the same taper as the rod at that point but 0.100” oversize and the apexes planed off to 0.050”. I then assemble the ferrule on the rod, impregnate the mating surface with poly-urethane, and then wrap the whole assembly in silk and apply the finish. 
I must confess that I had my doubts about the durability of these ferrules, but this one is holding up admirably, and the claims for smoothness and light weight certainly seem justified.
There is another type of bamboo ferrule, formed buy a swell in the rod section, I’ve not made one of these yet, but will certainly be making some.
Coming soon... Morticed rods.