A common optical pickup can be mounted in any of {HEAD ~ disc drive units} having {TAIL ~ respective pairs} of oppositely disposed guide shafts that are separated from each other by different distances 
having
A common optical pickup can be mounted in any of { HEAD ~ disc drive units } having { TAIL ~ respective pairs } of oppositely disposed guide shafts that are separated from each other by different distances
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH