The STIHL ROLLOMATIC(R) E Super guide bar is a solid-machined bar made of high-grade steel with the groove milled out and a replaceable sprocket nose assembly riveted in place. The sprocket is incorporated in the replaceable sprocket nose assembly of the bar and carries the saw chain from the top to the bottom of the bar. This not only reduces wear, but also enables the bar nose to be made considerably narrower. This type of construction is an advantage where extensive use is made of the bar nose (i.e. limbing and boring). All STIHL ROLLOMATIC(R) bars designed with a narrow nose help reduce kickback tendencies. And the sprocket nose assembly can be replaced several times before the whole bar is due for replacement, increasing the service life of the bar. | STIHL 28" 3/8-050 Guide Chainsaw Bar