This is a EMCH Log Periodic Mount and is manufactured from non-conductive material to minimise RF influence.
This device has been engineered for the EMCO log periodic series of antennas. It has been designed to sit onto the EMCO 5.2cm (2 Inch) square boom which has a series of ¾ Inch holes allowing a delrin screw (item 855) to grip the mount. The under surface has a ⅞ Inch UNF socket or it can be converted to receive a ¼ Inch UNC camera socket.