Preferably, the selector shaft 2 is driven by a brushless motor 5 by {TAIL ~ means} of a double planetary stage 6 and {HEAD ~ a toothed segment} 7 which engages a toothed wheel 16 that is preferably positioned in a housing element 17 
Preferably , the selector shaft 2 is driven by a brushless motor 5 by { TAIL ~ means } of a double planetary stage 6 and { HEAD ~ a toothed segment } 7 which engages a toothed wheel 16 that is preferably positioned in a housing element 17
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH