It fits on the Stihl MS500i, MS640, MS650, MS660, MS661, 056, 064 & 066 models. 20" OREGON Pro Forestry Kit - Guide Bar, 2 Chains & Filing Kit. The kit consists of a 20" PowerCut solid nose guide bar, 2 x 75EXL chainsaw chains and a 7/32" (5.5mm) filing kit.
eBay