San Francisco 49ers Battery Operated Lights are Officially Licensed N.F.L. Products. Each pin comes complete with an optional 36" lobster claw Lanyard Necklace, an On/Off button, 2 CR927 Batteries to power the piece, and 2 extra batteries for future replacement are included. This piece is perfect for the Big Game, whether you're inside the stadium, tailgating, or in the comfort of your own home! Just tighten the battery case and press the button to activate the flashing red and yellow LED ligths.