Bar nut retaining/captive style fits the following models:-
Genuine Husqvarna Part
545
555
T540 XP
T5365 LiXP
536 Lixp
550 XP/XPG
560 XP/XPG
Part no 505197301
Replacement bar nut to fit most chainsaws in the old and new range. Size - 18mm x 5mm Thread Size M8 FITS CHAINSAW MODELS 009, 010 AV, 017, 018, 019,...