For the small two-blade grinder in the lid that lets you probably "coarse" to prepare for later processing with corundum stick the knife, but was advised to be cautious: who spends because too much force or the knife with sheer pressure by the score draws, produces so much erosion that it is probably a knife with a delicate alloy more harm than good!
Overall, definitely a nice little gadget, not only for the pocket knife of the same brand!