I just ordered and received the below parts from my LBS and there is a slight error in Mitch's info below:
596164 (6mm bolt and T-nut): approx $50. This comes in a bag with TWO bolts and Two T-nuts. Based on what Mitch said, I ordered two, which got me 4 bolts and 4 T-nuts, which you don't need. Also $50 for two bolts and 2 t-nuts is a bit much.
The Mono Plugin was about $150, not the crazy $250+ that it was before. So that's a nice change. The mono slider that the bolts go through is about $10.
The slot in the new Mono Plugin is slightly wider than before to fit the 6mm bolts. If you wanted to live on the edge you could probably sand down an old mono extension to fit the new bolts and slider (if your old bolts broke and were replacing them anyway).
One thing I'm not thrilled about is the amount of torque it takes to tighten down extensions in the mono plug-in. It's not grabbing the extensions until pretty high torque levels so I'm a bit worried about stripping the bolts (note, this is still within the marked torque specs which I believe are 8Nm, but it just feels like I shouldn't need to crank down that much to secure extensions)
For those asking about the new Mono Plug-In, I wanted to give you the official update which I can do now!
So the new model retains the same look, but uses 6 mm hardware over the previous 5 mm hardware for added strength. In order to run the new Mono Plug-In, you will need to order the following (which you can actually order TODAY!):
Mono Plugin â€“ W582446
6mm bolt and T-nut â€“ 596164
(You will need TWO of these)
Mono Slider â€“ W582447