Homelite 307505003 Pack of 4 Chainsaw Tension Knobs Pack of 4 Replaces old part #s 678618002 and 518769001 Fits: UT10540 14" 35cc, UT10560 16", UT10580 18", UT10519 46cc, UT10522 46cc, UT10526 46cc, UT10526 46cc, UT10542 14 35cc, UT10562 16 38cc, UT10582 1842cc, UT10918 18" 42cc