Wondrous Item, very rare (requires attunement by a Rogue, Dex 15+, Proficiency with Daggers.)
A belt with 3 leather straps, each decorated with an onyx crystal. 3 daggers can be 'attuned' to the belt so that when the dagger collides with an object or creature it will return to the belt after 1 second.
Notes: Rogue, Dex 15+, Proficiency with Daggers.