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 can dissipate when placed in the sun or in a well-ventilated area for 2 to 3 days. It is recommended to remove the protective film before use. This device produces low-frequency electromagnetic waves and requires the use of headphones. Adjustable frequency: 0.01 to 100,000 Hz adjustable frequency range. The sine wave generator allows you to set the frequency according to your needs for efficiency and personalization. Default frequency is 7.83 Hz, and it can also be adjusted to 174 Hz, 285 Hz, 396 Hz, 417 Hz, 528 Hz, 639 Hz, 741 Hz, 852 Hz, 963 Hz, and other frequencies. Multiple waveforms: The audio generator offers multiple waveforms including sine wave, square wave, and reverse square wave, suitable for a range of applications in environments such as laboratories and studios. Promotes relaxation: The adjustable resonance generator emits sine waves, helping create a calming environment that may support improved mental state and relaxation. Makes a thoughtful gift for friends and family on birthdays, Christmas, and other holidays. Portable size: The sound generator measures approximately 5.9 x 5.5 x 1.2 inches, and the acrylic case measures approximately 6.2 x 5.8 x 1.5 inches, providing good protection. Compact design with USB power enables easy portability for use at home, work, or while traveling. Stable and reliable: The sine wave generator has a default frequency of 7.83 Hz. Sine wave voltage amplitude is 3V, and square wave voltage amplitude is 5V, ensuring stable and accurate signal output. Wide application: This adjustable frequency generator is suitable for various settings requiring signal generation and frequency adjustment, such as electronic equipment testing, device calibration, and scientific experiments. Frequency range: 0.01 to 3000 Hz.