Each tentacle on your LED Under the Sea Squid Hat lights up along with the eyes. The hat turns on with a simple flip of a switch. The battery pack is tucked away into the hat. NOTE: When you order 1 piece, you are ordering a set of 4 Assorted Color Hats. . Assorted LED Under the Sea Squid Hat Pack of 4 come in assorted colors of pink, green, and blue. Included are four AG10 batteries. Batteries are nonreplaceable for continued Squid fun!