After ink is filled through the ink filling hole 42 on the inner cover 40, {HEAD ~ a cylindrical element} 72 formed on the outer cover 70 is fitted in {TAIL ~ the cylindrical element} 42 a encircling the ink filling hole 42, thereby sealing up the ink filling hole 42 
is fitted in
After ink is filled through the ink filling hole 42 on the inner cover 40 , { HEAD ~ a cylindrical element } 72 formed on the outer cover 70 is fitted in { TAIL ~ the cylindrical element } 42 a encircling the ink filling hole 42 , thereby sealing up the ink filling hole 42
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH