Please read - check you saw, bar and chain setup as these models had multiple configurations  

Do not buy just because you have a 20" bar !!!

*** No Tape Measures Please - Use PITCH, GAUGE, DRIVE LINK COUNT AND MOUNTING TYPE    Saw model and bar length are not enough information to buy correct bar and chains.  Many models came with different Pitch chains, gauges and drive link counts that are all generically called 20"  

These are some of the saws this combo MAY fit : 

Stihl   024,026,028,029,030,031,032,034,036,038,039,040,041,042,044,045,048,056,064,066,E15,E20, 026C MS

360, MS361, MS440 MS441 MS660, 066 , same models in MS  

DOES NOT FIT ** 025, MS250, MS251 and family - these saws use the A074 mount - this bar will not work !

***  024, 026, 028, 029 and similar size MS models have D025 mount but may have come with .325 Pitch in .063 Gauge chain setups.  We cant emphasize this enough that you are sure you know which setup you are buying and to verify you are getting the correct bar and chains.   If your saw is setup for .325 pitch you will need to change sprocket or rim to match the 3/8 pitch.

Typical Replacement for  :   Stihl 3003-000-8921  Stens SN20-50A  Oregon 200SLHD025  Tilton T202WL4-2