A adapter module for ESP-01 Wi-Fi module 3.3V voltage regulator circuit and onboard level conversion circuit can make 5V microcontroller easy to use with ESP-01 Wi-Fi module Also, the item can be used with R3 or compatible board Working voltage: 4.5~5.5V (On-board 3.3V LDO Regulator) Working current: 0-240mA Interface logic voltage: 3.3V / 5V compatible(On-board level shift circuit) material: plastic Color: blue Package Included: 1 x ESP-01 Adapter Module Only the above package content, other products are not included. Note: Light 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.