Groove by Aerospaced 2" 4-Piece Grinder / SifterGroove by Aerospaced 2" 4 Piece Grinder Sifter The Groove by Aerospaced is a 4 piece grinder with a 2" diameter has a unique toothless system. That means less cleaning, and less opportunities for a tooth to break or dull. It's available in both black and red. Return policy We only accept returns for accessories if they are within 30 days, unused and unopened, or if they are being returned with a vaporizer under our 14 day satisfaction policy.