The MC95-220 provides a strong response to fields over the Extremely Low Frequency (ELF) and Very Low Frequency (VLF) ranges, with a wide maximum near 1.6 kHz, offering wideband accuracy for measuring magnetic fields from electrical and electronic equipment, including computers, transformers, power supplies, building wiring, electric panels, electric machinery, office equipment, appliances, dimmer switches, power lines and harmonics, ceiling tracks, pumps, audio frequency signals, aircraft (400 Hz), ships, subways and rail.