Batarangs

The Batarang is a weapon Batfamily members use throughout the Project Series.

Backstory
Bruce Wayne invented his Batarangs when forming his identity as the Batman, along with his other gear. Batman has been using his Batarangs throughout his whole career as the Caped Crusader, and they first appear in Project Batman 2.

History
Tim Drake first uses an early design of the Batarang in Project Robin 2, when he saves Batman from a common thug. It ressembles the appearance of a coat hanger. Robin frequently uses Batarangs in Project Batman 3 as well.

In Project Justice League, Batman gets a classic looking Batarang from his house.