The device has a built-in silicon label and can be used without a microphone. The lever can be used to switch display modes, and the encoder can be used to control sound effects. When used as a sound effect processor, the device must be powered independently, such as a 220v USB charger or a dedicated 12v input, otherwise it introduce display crosstalk. Made of high-quality materials. Easy to use. Input voltage:USB5V/DC7-24v Input power:1W Frequency response:50Hz-20kHz Sensitivity: 40db (@1kHz) Channel:dual channel/mono switchable Input interface:3.5mm unbalanced/XH2.54-3P Sampling rate:48KHz Input gain adjustment range:-6-+42db Output gain adjustment range:-52-+12db AGC adjustment rate:-3db-27db Pitch range:-8-+8 degrees EQ frequency:logarithmic 15 bands EQ data group:6 presets + 10 personal settings Colour:As Shown Material:Plastic Package Contents: 1 * Audio Spectrum Analyzer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.