Rotary 1617. SPROCKET CHAINSAW .325" X 7T. Fits 029, 034, 036, and 039 Stihl. Drum ID: 2.9880, Durm Depth: 11/16", Hole Size: 1/2", Shaft Size: .3937 or 10mm. Needle bearing included.

Replaces
HERR: 191-L7

Fits Models
STIHL: 024, 026 (Before#X258090