{TAIL ~ An instrument} is provided for working of surfaces of parts inside engineered cavities by means of a tool, with the possibility of simultaneous viewing of the site of {HEAD ~ the working operation} 
{ TAIL ~ An instrument } is provided for working of surfaces of parts inside engineered cavities by means of a tool , with the possibility of simultaneous viewing of the site of { HEAD ~ the working operation }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD