Keystone's battery insulator will protect battery and circuitry during shipping and handling. The insulator is to be pulled out from product to activate. Lettering and an arrow provide intuitive markings for proper use. It is made from a thin, flexible, strong polyester so the insulator can be pulled from battery compartment even if the compartment is closed. Part number 111 is for button cell through AAA batteries; part number 117 is for 12.7 mm coin cells and AA or larger cylindrical cells.