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 a well-ventilated area or under indirect sunlight for 2–3 days. It is recommended to remove any protective film before use. This device outputs low-frequency signals; headphones are required to hear the 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 in laboratories, studios, and educational settings. Compact and 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. Powered via USB for convenient use and portability. Signal specifications: - Frequency range: 0.01 Hz to 300,000 Hz - Default frequency: 7.83 Hz - Power supply: 5 V DC - Sine wave output amplitude: 3 V - Square wave output amplitude: 5 V Construction: Metal housing with acrylic enclosure. Package contents: - 1 x Adjustable sine wave resonance generator - 1 x Acrylic case - 1 x USB data cable Note: Color appearance may vary slightly due to screen settings and lighting conditions. Measurement tolerance: ±1–3 cm.