Air Filter Fits Stihl Back Pack Blower BR 340, BR 420, 4203-141-0301 & 4203-120-1500, 4203-007-1028, Stens: 102-414,102-412, Rotary 27-10963, 27-13159, Oregon 30-137, Brand New Air Filter Kit fits Stihl Back Pack Blower Fits Stihl BR340, BR340L, BR380, BR420 and BR420C, Rotary 27-10963, 27-13159, Oregon 30-137 Size: 5-1/8" (L) x 3-1/2" (W) x 1-1/2"(H) Does NOT come with Pre-Filter