I did a lot of research and bought this one. Best bang for the buck. My MB sits out in the weather in Fla. I am very happy with it. Size 4 fits my 300SD.
Hope this helps

__________________

1984 300SD 175,000 Miles
1987 GSXR 1385cc
1985 GSXR Limited Edition 750cc
2005 Suzuki Burgman 650cc