Florida Marine Research - Hermit Shell 2Pk Lg 6PcSmall Animal: OrnamentsPackaged Large Natural Shells 2Pack Two larger shells up to 4 inches in size As a crab grows and begins to protrude out of its existing shell a new and larger shell becomes imperative Empty shells of similar size to the crabs proper fitting shell will prevent any potential aggression of one crab toward another Aggression is rare, howeverLarge2 Pk6 PcShip Dim: 9.8x6.13.8 inShip Wt: 1.55 lb