I have been given an OPI stem and I'm not sure what length or rise the stem is. I could try measuring it but is there anyway of telling from the codes on the stem and face plate.

There are four codes.

6N-m torque setting for face plate bolts I assume.

100-D12 possibly 100mm long stem, not sure what the D12 is for.

Inside the stem there is a RE28 code.

On the face plate the code is RF11.