Materials: This Schumann Wave Generator features good frequency stability and programmable frequency modulation technology for adjusting frequencies from 01Hz to 100000Hz. Choose between a model with an acrylic shell or without, based on your needs Digital Circuit Crystal Oscillator: Enjoy improved resistance to interference with the crystal oscillator frequency reference in this Pure Sine Adjustable Frequency Generator. The Type-C power supply interface ensures reliable power delivery Wide Frequency Range: With a frequency range of 01Hz to 100000Hz, this Schumann Resonance Pulse Sine Wave Generator is versatile for various applications. The 5mm audio frequency output allows for easy connectivity Customizable Frequencies: Take control of the signal output with the programmable frequency modulation technology of this Adjustable Frequency Generator. Easily adjust frequencies to suit your preferences and needs Compact and Portable: Whether you choose the model with an acrylic shell or without, this Schumann Wave Generator is designed for . Its compact size and power-off storage make it for on-the-go use Specification: Color: green. Material: PCB. Size: Approx 20*14*4CM/7.87*5.51*1.57inch. Note: There might be a bit color distortions due to different computer resolutions. There might be a slight errors due to different hand measurement. Package Includes: Without housing: 1* Schumann wave generator 1* power cord With housing: 1* Schumann wave generator 1* power cord 1* housing set