shape of the tongues 54 match slots not shown formed within the sockets to key the swivel joints with the housing this keying feature aligns the apertures of the first portions and the housings so that the screws can be easily inserted therein although set screws 52 are described and shown it is to be understood that other attachment means may be used such as a pin as shown in fig2 the coil 22 is attached to a wrist strap 56 the strap 56 is constructed as one piece and preferably has hook and loop material to provide an easy means of attaching and detaching the strap 56 to the wrist of the rider the strap 56 has a plurality of hexagonal shaped apertures 58 that reduce the weight of the strap 56 without significantly decreasing the strength of the same extending from the strap 56 is a housing 60 with a socket 62 aperture 64 and screw 66 as described above the strap 56 is attached to the coil 22 by inserting the second portion 46 of the second swivel joint 42 into the socket 62 of the strap housing 60 and then screwing the set screw 66 into the housing 60 and through the aperture 48 of the second portion 46 the strap 56 is attached directly to the coil 22 without any intermediary ropes or loops providing.