This is Stihl's OEM chainsaw bar from Stihl. Stihl Rollomatic E Super chainsaws bars (also known as ES bars) are the premium sprocket nose chainsaw bars available from Stihl. Bars are made machined from a single piece of rigid steel. The replaceable sprocket nose tip is securely fastened by three rivets. The nose sprocket is sealed to keep dirt and corrosive material out, therefor never needs to be greased. Rails on the bar and nose are induction hardened for long life. Angled oil delivery hole increases flow rate and reduces clogging of lubricants. This bar has an increased risk of kickback potential (yellow color coded bar) and should be used by trained professionals only.