Phantom Limb

Wondrous item, uncommon (requires attunement).
  This nebulous, floating cluster of green-blue light replaces a hand, arm, foot, leg, or similar absent appendage when you attune to it. Despite its spectral appearance, the phantom limb is solid and can’t phase through any material or creature. You can make it appear or disappear at will (no action required). When present, it functions as the limb its replacing.
  If you have multiple phantom limbs, they count as a single magic item with regard to the number of magic items to which you can attune.
  As an action, you can detach the limb. While your phantom limb is detached it acts as described by the mage hand spell. You can use an action to reattach your limb as long as it is within 30 feet of you.
  Rare variant. The reach of your unarmed strikes made with the phantom limb and attacks you make with weapons with the light property held by the phantom limb have their reach increased by 5 feet.