A fire extinguisher accessory device for providing oral instructions for using a fire extinguisher comprising a housing, a digital memory circuit disposed inside the housing, wherein the digital memory circuit can provide oral instructions for using the fire extinguisher such as “pull,” “aim,”...http://www.google.es/patents/US7907048?utm_source=gb-gplus-sharePatente US7907048 - Fire extinguisher accessory device providing voice instructions
Fire extinguisher accessory device providing voice instructions
