Stihl 3667 005 0081 Oilomatic Duro 26RD3 81 Carbide Chainsaw Chain, 20" Genuine OEM Stihl Part The STIHL RAPID Duro 3 Chain Is A Low-Kickback Chain With Standard-Sized Cutters The RD3 Is Extremely Durable .Especially Suited For Cutting Dirty Wood, Treated Wood, Roots And Hardwoods, Which Would Normally and Quickly Dull Conventional Chains .325" Pitch; .063 Gauge; 81 Drive links; Fits 20" Bars Fits Various Stihl Models Including: 025, MS 250, MS 251