Adding a bit to training - Groundwork using a D ring Snaffle with copper rollers

Penny's owner would like her ridden in a snaffle bit as well as a hackamore.
So I will testing which bit works the best.
This is the basic groundwork part of the test.

D Ring bit,D ring with rollers,choosing a bit,copper roller bits,snaffle bit,using a snaffle,#bit,