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 will introduce display crosstalk. Made of high-quality materials. Easy to use. Input voltage:USB5V or DC7-24v Input power:1W Frequency response:50Hz-20kHz Sensitivity: 40db ( 1kHz) Channel:dual channel or mono switchable Input interface:3.5mm unbalanced or XH2.54-3P Sampling rate:48KHz Input gain adjustment range:-6-and42db Output gain adjustment range:-52-and12db AGC adjustment rate:-3db-27db Pitch range:-8-and8 degrees EQ frequency:logarithmic 15 bands EQ data group:6 presets and 10 personal settings Colour:As Shown Material:Plastic Package Contents: 1 x 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.