The FS-409 oscilloscope has dual channel, multiple testing application equipment. It built-in at least 2 testing equipment in one. FS-409 is a 40MHz analog oscilloscope built-in a 5MHz Function Generator and a 50MHz Auto-Range, Auto Gatetime Counter. Its function generator and counter can be operated independently or jointly. With frequency bandwidth DC to 40 MHz at -3dB. Waveforms are accurately presented on the oscilloscope?s 6inches rectangular CRT screen with internal graticule.