The SparkFun ESP8266 WiFi Shield is an Arduino compatible shield for the ESP8266 WiFi SoC – a leading platform for Internet of Things (IoT) or WiFi-related projects. There are a variety of designs based around the ESP8266, including tiny, modular boards and more accessible development boards like our very own SparkFun ESP8266 Thing.
This is a small built-in spring GSM antenna with IPX connector. Its working frequency is 900/1800 MHz which meets most requirements of GSM applications. Its very compact size makes it easy to carry and use.