The FSA Mega EXO SL-K bottome brackets work with the K-Force Light and SLK Light cranks only. The left cup is slightly more narrow so they will not work on non-Light models.
Other than the diameter-specific bearings for FSA Light models, the BB-8681 has the same features as the standard Mega-EXO BB-8000. The cups are forged, then CNC'd and anodized. Inside the cups, quality steel bearings are pressed in, then sealed with external plastic shields and double O-ring seals. Alloy, platinum-look finished center sleeve snaps into the drive and non-drive side cups. Installation and removal is taken care of with any standard Shimano-style outboard bb tool. Quality threads ensure easy installation.