The WPC.25A 2.4GHz Ceramic Patch Antenna with cable works on Wi-Fi, Zigbee, Bluetooth and ISM band at 2.4GHz. This antenna comprises of a 2.4GHz 25*25*4mm embedded patch with mini-coax cable and connector for connectivity and a PCB carrier to mount the antenna. The WPC.25A is circularly polarized which is more suitable to avoid interference and phase cancellation from reflections. The antenna has its own ground PCB carrier and is therefore ground independent. Many module manufacturers specify peak gain limits for any antennas that are to be connected to that module. Those peak gain limits are based on free-space conditions. In practice, the peak gain of an antenna tested in free-space can degrade by at least 1 or 2dBi when put inside a device. So ideally you should go for a slightly higher peak gain antenna than mentioned on the module specification to compensate for this effect, giving you better performance.