4244 182 9502 STIHL Choke Knob OEM Genuine Part 4244-182-9502, 42441829502.

Fits these STIHL models:

Stihl BR 350 & BR 430 Backpack Blower
Stihl BR 450 C-EF Backpack Blower
Stihl SR 430 Mistblower
Stihl SR 430 Z Mistblower
Stihl SR 450 Mistblower
Stihl SR 450 Z Mistblower

YSK 700027

SR-4