The PI-4100 field strength meter with extended low-frequency tuning, covering 200 kHz to 5.1 MHz for LF and MF work.
Same instrument as the standard PI-4100: 22 µV/m to 50 V/m range, built-in GPS logging, spectrum display, removable calibrated loop antenna, internal calibration source, onboard data storage and rechargeable NiMH battery.