Oregon 71-104 Innertube, 18 x 850-8/950-8 This INNERTUBE 18X850/950-8 STRAIGH is high quality replacement part number 71-104 and OREGON description is INNERTUBE 18X850/950-8 STRAIGH OREGON is a world leader of saw chain, guide bars, sprockets and forestry accessories. OREGON is part of BLOUNT and is also a leading manufacturer and supplier of lawn mower blades and other outdoor equipment parts.