Lightning claws are commonly used as matched pairs. They consist of a number of blades extending from a housing on the wrist and back of the hand. Each blade is a mini-power weapon in its own right and, if they hit, one blade or another is likely to wound.
Lightning claws ignore Armour Saves and may re-roll any To Wound dice that fail to wound once each. The only weapon that can provide an additional close combat weapon attack bonus for a model with a lightning claw is another lightning claw.