STIHL chain saw chain guide bar For models: 017 , 018 , 019 T , 021 , 023 025 , MS 171 , MS 180 , MS 181 , MS 190 MS 190 T , MS 210 , MS 211 , MS 230 MS 231 , MS 250 , MS 251 Part No.: 402717 61 Original part No.: 1123-162-7800 STIHL MP