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