Features: VFD253 integrates mutiple functions into a whole: As an audio spectrum analyzer: adopts dedicated green VFD display screen with 25 x 15 high resolution, the accuracy of each frequency band. As a Bluetooth receiver and audio switcher: besides microphone pickup, also with Bluetooth 5.0 and 2 groups of 3.5mm AUX input, works perfectly with your phone/PC/game player/amplifier/speaker etc. As a high-precision clock: using RX8025T built-in crystal oscillator whose clock accuracy is ±3ppm, year error within 1 minutes, very cool and interesting. Wide frequency range & special AGC display: 80Hz-16KHz frequency sweep, high-precision display even can do frequency point test. Speical AGC algorithm and customized output curve, ideal visual effects even the input signal is in a small to large range, avoid that no display when input low and display in full screen when input high. Many adjustable items & display effects: gain, brighntness, falling speed of main light column, holding time and falling speed of the can be adjusted separately. 5 music spectrum display mode and 2 clock display mode, all settings with power-off memory function, no need to set again after restarting. Attractive looking and convenient use: with remote control, easy to adjsut all settings and see the music level status in real time and every slight change of sound.CNC machined aluminum and transparent acrylic case, both solid and beautiful, compact design not occupy your desktop space. Warm tips: 1. For safe shipping, the remote control may not include batteries (2*AAA), please prepare by yourself. 2. 3.5mm AUX1 and 3.5mm AUX2 cannot input at the same time, only one audio source channel (MIC / Bluetooth / IN1 / IN2) can input at a time. Parameters Display screen: VFD (Vacuum Fluorescent Display) Resolution: 25 x 15 Frequency range supported: 80Hz-16KHz Display item: music spectrum / clock Audio signal input: MIC / Bluetooth 5.0 / 2 groups of 3.5mm AUX Audio signal output: 1 group of 3.5mm AUX Work mode: 1. Auto mode (display music spectrum when music input, display clock mode when no music input) 2. Clock display mode (always) Clock display: 2 kinds Music spectrum display : 5 kinds Music display mode: AGC+customized output curve (Real output / Smooth output) Adjustable items: main light column falling speed / holding time / falling speed Brightness adjustment: 5 levels+auto adjustment Gain adjustment: 5 levels Power-off memory function: support Remote control: support Working voltage: DC 5V Color: As Shown Material: Acrylic Package Contents: 1 x Finished VFD spectrum 1 x USB power cable 2 x foot pads 1 x remote control (without batteries) 1 x English manual 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.