9180581 Boom Cylinder Seal Kit Fits Hitachi EX300-5-ZX370One New Aftermarket Replacement Seal Kit Fits Hitachi Excavator Boom LH Models: EX300 5, EX330 5, EX350 5, EX370 5 (H,HD,K,&LC) (All SN: 20001 , Cyl #: 9164872), ZX330, ZX330LC, ZX350LC, ZX350LCH, ZX350H, ZX350K, ZX350LCK, ZX370, ZX370MTH (All SN: 030001 D04 07, Cyl #: 9186601) Fits Hitachi Excavator Boom RH Models: EX300 5, EX330 5, EX350 5, EX370 5 (H,HD,K,&LC) (All SN: 20001 , Cyl #: 9164874), ZX330, ZX330LC, ZX350LC, ZX350LCH, ZX350H, ZX350K,