Twin Blades

The Twin Blades were a pair of short blades forged from the same steel by the same blacksmith. Though intended to be wielded as a pair, their name could be misleading; they were not identical. The larger of the two resembled a butcher knife with a nearly rectangular, albeit curved, blade. In contrast, the smaller counterpart—meant to be wielded in the offhand—was in essence an enlarged scalpel.

Reference

 * Assassin's Creed: Origins