Stihl Auto Cut 40-2 mowing head with 2.7mm cutting line suitable for mowing grass around obstaclesand light vegetation. This Stihl head holds double or quadruple line for mowing & thinning. The nylon cutting line is automatically readjusted when the cutting head is tapped against the ground. Can be used with pentagonal, round or square 2.7mm nylon line. Fits Stihl models: FS310, FS360 C-E, FS400, FS400-K, FS410 C-E, FS450, FS450-K, FS460 C-EM, FS480, FS490 C-EM Only approved for use with guard