Siretta DELTA Series Direct Connect Antennas - Siretta DELTA5A/x/SMAM/RP/S/17, The Delta 5A from Siretta is a direct connect stubby antenna measuring 100mm in length. It is a ¼ wave, helically wound, omni-directional antenna with a centre frequency of 868MHz. It is far more focused than wide band antennas, such as quad band GSM, providing far superior performance. This does however mean that the Delta 5A is limited to 868MHz only applications. 868MHz resides within the Industrial, Scientific and Medical (ISM) band. Common applications for ISM antennas are low power short range applications such as: wireless sensory monitoring, street light control, smart metering and security systems, etc.The bottom of the antenna and the connector are 'flush' with one another, in other words, there is no 'skirt' or overhang. Siretta DELTA5A/x/SMAM/RP/S/17 868mHz 100mm Flexy Rubber 1/4 Wave Whip Antenna