What is a Slipperential?

[Finnster]

? from other thread:

Question tho. Are all the replacement parts custom to RCM? Obviously the spur and case and all, but what about the internal gears, slipper pads and other misc things? I know at one point Mike said he wanted avoid using OEMs for parts as they may discontinue parts at any time.

What is the price? Missed that too, tho we'll see it soon enough.