This means the first part of the housing terminates with one front side of {HEAD ~ the cartridge} or the front side projects somewhat over {TAIL ~ the first part} of the housing 
This means the first part of the housing terminates with one front side of { HEAD ~ the cartridge } or the front side projects somewhat over { TAIL ~ the first part } of the housing
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH