Hayley they look like a very cool tool!
I use a pair of Murrini hemostats - the best investment I ever made. I've even got used to manipulating then so I can hold them the same way as I do a rod. I can use rods down to the last 3/8"
They'll hold the thickest rod you can imagine, but they are no good for any diameter smaller than approx 3mm... & the last lot of ASK colours I got are more like stringers than rods!
Think I'll have to look at a pair of the Micro Merikals