Which dualsky ESC

[brown4s]

Advice please guys,

built my durango dex210 and decided to go with dualsky as electrics package but can't decide on which esc, the XC850 or XC870 ?

The 850 comes with instructions but no fan

The 870 is the latest but doesn't come with instructions but does have a fan but I can't see how it is attached as the heatsink in angled and there don't appear to be any screw holes like on the LRP flow

????????????

Your thoughts please

Regs