The training apparatus 1 wherein each of said at least one transceiver is an ultrasonic transceiver and {HEAD ~ each} of {TAIL ~ said at least one reflector} is an ultrasonic reflector 
of
The training apparatus 1 wherein each of said at least one transceiver is an ultrasonic transceiver and { HEAD ~ each } of { TAIL ~ said at least one reflector } is an ultrasonic reflector
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH