For the WiFi module A adapter module of ESP-01. The 3.3V voltage regulator circuit and onboard level conversion circuit make it easy for 5V microcontrollers to be used with the ESP-01's WiFi module. In addition, the product can be used with UNOR3 or compatible boards. Design: Compact and robust design, perfect for long-lasting use in various environmental conditions. Working voltage: 4.5-5.5V (onboard 3.3V LDO regulator) Working current: 0-240mA Interface logic voltage: 3.3V/5V compatible (onboard level conversion circuit) Due to different batches, there may be differences in product appearance and printed text, which will not affect use. Color: Blue Material: PCB Package Contents: 10 sets x WiFi Wireless Adapter Module (10 adapter plates + 10 ESP01) Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm.