Main control chip: ESP32-WROOM-32U, Flash 4MB, Wi-Fi + Bluetooth dual-core module Display technology: 2.8-inch 320x240 resolution, IPS full-view LCD screen, with resistive touch Control method: default numeric keyboard input and knob tuning method, also supports touch screen firmware Antenna interface: full-band external antenna, standard SMA male screw female connector. Speaker output: TI audio amplifier chip TPA6211A1 is used to drive 82x43mm dual-diaphragm large sound cavity speaker, power 4Ω/3W, lower output noise and less distortion. Headphone output: AD headphone amplifier chip MAX97220 is used, standard 3.5mm audio connector output, dual amplifier design for speakers and headphones, optimized separately without affecting each other. Battery parameters: 3.7V/5000mAh, 18.5Wh Current consumption: about 3.7V/350mA, use time is about 15 hours. Communication interface: built-in CH340 USB to serial port chip, external communication through TYPE-C interface Due to different batches, there may be differences in product appearance, color, and printed text, which not affect the use. Type:TEF6686 Full Band Radio High Sensitivity Receiver Color:As Shown Material:PCB Package Contents: 1 * Radio 1 * Donut antenna 1 * Touch pen 1 * TYPE-C data cable 1 * Storage bag 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.