Air Filter Fit Stihl Back Pack Blower BR320 & BR400: 42031410300, 42031410310, 42030071025, 42011401805 Air Filter Kit Fits Stihl Back Pack Blower Model # BR 320 & BR 400 OEM P/N: Stihl P/N: 4203-007-1025 Air Filter Kit Includes: 4203-141-0300/4201-140-1805 (Air Filter) & 4203-141-0310 (Felt Wrap Pre-Filter) Size: 1-3/4" (ID) x 2-7/8" (OD) x 1-5/8" H