ORIGINAL STIHL hedge trimmer air filter for models HS81T HS 81 T HS86T HS 86 T HS81R HS 81 R HS86R HS 86 R HS82R HS 82 R HS82T HS 82 T HS87R HS 87 R HS87T HS 87 T Part No.: 42371201800 4237-120-1800