Now this is just pure speculation, but what if the child ends up with a green kyber crystal at some point!? Each stone is cast in a translucent green resin. It's then painted and weathered by hand. Finally it is finished with an extremely fine interference mica powder. The SMD/PCB unit is embedded into the stone with a small battery housing slightly exposed on the underside which can easily be opened with a twist action to change out the batteries as needed. It also holds secure to the Sideshow versions magnetic hand. There are 2 modes: ON and OFF. Testing so far has shown that these will stay on solidly lit for at least 30hrs before needing a battery change! Turn clockwise to turn it on and counter-clockwise to turn it off. Continue turning counter-clockwise to unscrew the battery compartment completely. It uses TWO 30 mAh 3V lithium button cell batteries (CR 927) .  Each stone measures approx. 1 1/2" long.These are in-stock, ready to ship usually within 1 week of ordering!