Finned/heatsink - semi-metallic compound, but on a heatsink. Marked improvement in thermal performance.
 
Compatibility
 
Shimano - most SLX, XT and XTR calipers, assuming clearance for fins.
 
M615, M666, M675, M785, M985, M987, M988, M6000,
M7000, M8000, M9000, M9020, R315, R515, R785, RS785, S700
Not compatible with M8120 calipers, or other four piston Shimano calipers; these generally take a 'Saint' pad. 
 
FSA K-Force DB-XC9000, Afterburner DB-XC-9150