SRD:Metaphysical Claw

If you have a claw attack (either from an actual natural weapon or from an effect such as claws of the beast) or a bite attack (which could be a natural bite attack or one you gain by means of the power bite of the wolf ), you can use this power to provide one of your natural weapons a +1 enhancement bonus on attack rolls and damage rolls.

Augment: If you spend 4 additional power points, this power’s duration increases to 1 hour per level.

In addition, for every 4 additional power points you spend, this power improves the natural weapon’s enhancement bonus on attack rolls and damage rolls by 1.