and is a so called three axis bird in the shown example with three wings 52 it will be 120 degrees between the wings 52 referring now to fig6 which shows details of the main body 53 the main body 53 is preferably elongate and tubular and is at its ends provided with connection means 54 a and 54 b adapted for mechanical and electrical connection in series in a multi section streamer of the kind being towed behind a seismic survey vessel the connection means 54 a b are for this adapted with corresponding connection points not shown at each end of each streamer section which connection points normally are used to connect two streamer sections together the main body 53 is formed by four parts assembled together into one unit which parts include a conical end part 55 a main part 56 a lock disc 57 and a end part 58 the connection means 54 a b are arranged at the conical end part 55 and end part 58 respectively referring now to fig7 which shows a split view of the main body 53 showing details of the important parts of the main body 53 the conical end part 55 is mainly tubular with a tapering end against a central projection 59 in which projection the connection means 54 a are arranged against.