1. Working voltage: 4.5V-5.5VDC (DC socket power supply, positive inside and negative outside, do not connect in reverse. 2. FM range: 87MHZ-108MHZ. 3. FM step: once for 0.1MHZ, long the FM key to increase or decrease continuously. 4. Function: digital display frequency function, power-off memory function, power saving function; 5. Power-off memory function: after turning off the power, turn on the power again, the radio station before the power off be played.<br><br>Power saving function: Each time the power is turned on or the FM button is pressed, the digital tube displays the frequency for 5 seconds, and the digital tube display automatically turn off after 5 seconds. There are two reasons for this design. One is to save power, and the other is that the digital tube interfere with the sound when it is displayed. Turning off the digital tube display make the sound more beautiful. Uses: homemade digital radio, single-chip computer learning, electric vehicles and motorcycles, etc., add radios This product is a loose part and needs to be welded by yourself Color: As shown Material: ABS+PC<br><br>Package Contents: 1 x radio production kit<br><br>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.