21 ELECTRICAL SWITCHES, RELAYS, CONTACTORS, SOLENOIDS, COILS, VOLTAGE REGULATORS, FUSE BLOCKS, RESISTORS, TERMINALS AND SOUNDERS; ELECTRIC BLANKET CONTROLS; ELECTRICAL MOTOR STARTING CONTROLS; ELECTRICAL ALARMS RECEIVING AND SIGNALLING UNITS; METAL ENCLOSURES AND PANELS FOR USE WITH ELECTRICAL SWITCHES, RELAYS AND CONTROLS; ELECTRICAL IGNITION SYSTEMS FOR GAS BURNERS AND THEIR PARTS-NAMELY, ELECTRICAL IGNITERS, FLAME DETECTOR SWITCHES, AND SAFETY SWITCH CONTROLS