Drove over 100 miles, round trip, to get to my nearest CIH dealer. Picked up 2 gallons of Hy-Tran oil. Nowhere on the container does it indicate the spec number. Only shows MAT spec. The counter man couldn't answer my question as to the required spec, B-6 or 1209, for my 1811. I can only assume that it's the correct oil for the hydrostatic tranny. At $35 a gallon I'm hopeful.