18"  Bar  for MS251 

 will also fit  (according to Stihl ) 009, 020, 200, 230, 231, 241, 250, 251

.325 pitch

.063 gauge

 popular hard to get WOOD BOSS BAR, came with MS251's

All OEM Stihl parts

18" bar # 3005 810 4717  - 7 teeth drive sprocket, 68 drivers, .325

 shipped in a box, not an envelope.  From USA, Not China.  genuine Stihl part

very well packed and shipped fast. 

Make sure it fits, no returns