A device for optical scanning of markings, such as barcodes, has at least two transmitters that send light beams at different angles toward a rotating polygonal mirror, which deflects the light beams onto the markings being scanned. The foamable igniter composition includes a fluoropolymer binder oxidant, a plasticizer effective to render the fluoropolymer binder oxidant flexible, a metal fuel that is reactive with the fluoropolymer binder oxidant, a blowing agent effective to render the foamable igniter composition porous, and a crosslinking agent effective to structurally stabilize the foamed igniter substance. An alignment guide receives the two guide posts. The induction-heatable objects are exposed to a rapidly-changing magnetic field which causes current to flow within the induction-heatable objects.