Western Cullen Hayes AAMBFL is designed to be used with Western-Cullen-Hayes Model HB or HBXS sliding derails. When the derail is placed in the derailing position, the AAMBF raises to provide Blue Signal protection in compliance with FRA and OSHA requirements. The AAMBF incorporates a gear reduction box and a 360 degree articulating sign shaft for smooth operation, reducing damage to the unit if accidentally struck by rolling stock. Battery operated Blue Light with 12 volt bulb. Uses two 6 volt lantern batteries (batteries NOT included). Photo cell controlled. 7" Blue Lens. Installs on staff of flag or can be used separately on ground. Special fastener for theft protection (wrench provided).