The TDI Astro MP brings a fan favorite on Earth in to orbit. The Astro MP includes a gray hard plastic sheath with belt clip to keep your knife from floating away. Ideal for opening freeze-dried food, mail from home, repairs to the ship, and self-defense. The TDI Astro MP brings a fan favorite on Earth in to orbit.??The Astro MP includes a gray hard plastic sheath with belt clip to keep your knife from floating away.??Ideal for opening freeze-dried food, mail from home, repairs to the ship, and self-defense.