The cap is tapered in shape, having a wide opening at the end which connects to the cylinder so as to minimize the risk of contact with the needle when {HEAD ~ the cap} is positioned on {TAIL ~ the cylinder} 
is positioned on
The cap is tapered in shape , having a wide opening at the end which connects to the cylinder so as to minimize the risk of contact with the needle when { HEAD ~ the cap } is positioned on { TAIL ~ the cylinder }
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 OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL