Oregon 90PX chain offers higher chain efficiency, ideal for small, low powered saws great for landscapers and homeowners. The 0.043 in ga narrow kerf cutting systems increase efficiency. They need less power from the saw than standard cutting systems. Top-plate filing Indicators make accurate sharpening easier. Top-plate filing Indicators make accurate sharpening easier. For saw sizes up to 42 cc. LubriTec keeps your chain and guide bar oiled for less friction and longer life.