Four Channel Real Time with 60 On/ Off Setting uses one channel to control school bell or factory siren and comes with 2 On/Off settings each in channel 2, 3 and 4. Johnson & Nelson manufactures Four Channel Real Time with 60 On/ Off Setting. Johnson & Nelson also offers electronic products like STD locks, 2 line conference telephone, auto caller and Multi channel real time switch. The Four Channel Real Time with 60 On/ Off Setting of model number TOS4S also provides an impression of occupancy to act a deterrent to thieves and finds application in factories, offices, schools, colleges, flats, houses etc.