thinkpad yoga 12 Pen?

Have a yoga 12 (active digitizer..). I have the stylus that comes with the yoga but looking for other option(s). Would like a two button with eraser. I am really not sure what I'm looking for to determine compatibility. Anyone out there point me in the right direction?

Main purpose will be note taking and some drafting..not an artist by any stretch... Thanks.

 

It's traditional EMR Wacom, meaning these will work:
http://forum.tabletpcreview.com/threads/tabletpc-compatible-wacom-pens-surface-pro-pro2-only.55416/

Also all pens that work with the IBM/Lenovo x61t, x220t, x230t, Thinkpad Tablet 2, Thinkpad 10 will work.

 

When I owned the TPY12" Gen 1, I preferred using the msft surface pro 1/2 pen on it. It had a nice feel on the matte finished screen.

 

For my TPY 12, I have a Wacom CS-400 Bamboo feel carbon (warehouse deal for half the price) and i really like it very much. With the white tip, it feels just great (2 kinds of tips are included).
Can totally recommend that.
Has only one button though. But I don't know if there even are some with two buttons...

P.s. TPY 12 has no active pens. Your model has a passive pen - as JoeS already mentioned. Just to clarify. You are looking for a normal EMR Wacom or compatible pen.