DIY ESP8266 ESP-01S Wireless Wifi Sensor For Arduino ESP-01 Advanced Version Wireless Transceiver Wireless Standard:802.11b/g/n Frequency Range:2.4GHz-2.5GHz(2400M-2483.5M) Data Interface:UART/HSPI/I2C/I2S/Ir Remote Control/GPIO/PWM Operating Voltage:3.0-3.6V(We recommended 3.3V) Operating Current:Average 80mA Operating Temperature:-40~125 Wireless Network Mode:station/softAP/SoftAP+station Safety Mode:WPA/WPA2 Encryption Type:WEP/TKIP/AES Network Protocol:IPV4,TCP/UDP/HTTP/FTP Package Included: 1PCS x ESP-01S ESP8266 Serial to Wifi Wireless Transparent Transmission Module