"C" Can XL

Hello,

I just noticed something I'd not seen before in the store, a Feigao 540C XL - what is this? How does it compare to the regular Feigao 540 8XL type motors? I can see the "C" can motor has a heat sync, does it also screw together? I popped two Feigao "L" series motors and since getting the RC Monster Heat Sync/can holder I'm all set.

How does the 540C XL compare with some of the BK XL motors?

Funny, when there was one choice I actually understood all this now I'm confused.

Thanks,