Carburetor for Stihl 4203 120 0601,4203 120 0603,4203 120 0605 Quality Aftermarket Carburetor Fits STIHL BR420, SR420 Replace STIHL4203 120 0601,4203 120 0603 Replace STIHL 4203 120 0605,4203 120 0607 Replace Walbro HD-4A,HD-4B,HD-13B