I am looking to buy a benchmark single trigger frame from PTP but am confused.

What is the difference between the 3: RT, RT Pro, MM2000/MM2K9?

From their website: "Please note that the RT frame fits Automag RT/RT Pro and Micromag 2000/MM2k9. Standard Automag/Classsic and pre-2k Micromag style frames are sold out at this time."

http://www.proteamdirect.com/noname2.html

I am looking to use this on a regular old AGD Minimag.