Just to give you a little history lesson. For Stihl to sell their saws in Canada the Canadian importing laws states that Stihl saws have to have a Canadian made product on it,so Oregon bars from Oregon's Canadian plant in Guelph,Ontario had to be used on the powerheads in the most common sizes under 28".Before Oregon it was Windsor on Stihl up until 1987, when at the time I raised hell through Chainsaw Age Magazine about the problems the oilholes on the Windsor bars not being blind drilled [one rail drilled through] and the plugged up oil holes were blowing the oil pump hoses off the 034s and the plugs out of the 038s pumps. The Oregon blind holes worked fine on the Stihls .After discussion with Stihls German factory engineer Yurgen Wolf the Windsors were eventually dropped and the Oregons bars have been on board ever since.