You receive: This product includes a resonance generator, an acrylic case with a small magnet, and a USB data cable. Note: The acrylic case may have a slight odor, which will dissipate naturally when placed in sunlight or a well-ventilated area for 2–3 days. It is recommended to remove any protective film before use. This device generates low-frequency electromagnetic signals and requires headphones for audio output. Adjustable frequency range: 0.01 Hz to 100,000 Hz. The sine wave generator allows user-defined frequency settings for flexibility and precision. Default frequency is 7.83 Hz; other preset frequencies include 174 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, 639 Hz, 741 Hz, 852 Hz, and 963 Hz. Multiple waveform options: sine wave, square wave, and inverted square wave — suitable for various applications including laboratory and studio environments. Portable design: The generator measures approximately 5.9 x 5.5 x 1.2 inches; the acrylic case measures approximately 6.2 x 5.8 x 1.5 inches. Compact size and USB-powered operation make it convenient for travel and on-the-go use. Stable and reliable performance: Sine wave output voltage amplitude is 3 V; square wave output voltage amplitude is 5 V. Designed for consistent signal accuracy. Wide application: Suitable for electronic testing, equipment calibration, scientific experiments, and educational purposes. Specifications: - Frequency range: 0.01 Hz to 300,000 Hz - Default frequency: 7.83 Hz - Power supply: 5 V DC via USB - Sine wave voltage amplitude: 3 V - Square wave voltage amplitude: 5 V - Color: As shown - Materials: Metal + acrylic Package contents: - 1 x Adjustable sine wave resonance generator - 1 x Acrylic case - 1 x USB data cable Note: Actual product color may vary slightly due to screen settings and lighting conditions. Measurement tolerance: ±1–3 cm.