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