Features: Uses a low-temperature drift crystal oscillator and high-precision DDS frequency synthesis technology for high frequency stability, with resolution and low-frequency accuracy up to 0.001 Hz. Supports up to 13 standard waveform outputs, including sine, square, triangle, forward sawtooth, reverse sawtooth, ECG, half-wave, Lorentzian, Gaussian, Sinc, exponential rise, exponential fall, and 7.83 Hz Schumann wave. Equipped with a 1.8-inch color TFT LCD display and digital keypad for direct frequency input, enabling intuitive and convenient operation. Includes auto power-off timer, signal LED brightness adjustment, and screen backlight brightness adjustment. FG-300 is a multifunctional, high-precision, portable signal generator suitable for electronic R&D, production testing, education, maintenance, and audio testing. Features an onboard spiral antenna optimized for Schumann wave generation. All settings are automatically saved and retained after power cycling. Specifications: Frequency range: - Sine wave: 0.001 Hz to 200 kHz (flat output amplitude up to 100 kHz; amplitude decreases and distortion increases above 100 kHz) - Other waveforms: 0.001 Hz to 20 kHz (maximum adjustable frequency is not strictly limited; higher frequencies may result in increased distortion and instability) Output amplitude: 2.5 V Output impedance: 330 ohms Display: 1.8-inch TFT LCD Power supply: USB Type-C Color: Green Construction: PCB, electronic components, and plastic casing Slight variations in printing or silkscreen appearance between batches do not affect functionality.