High performance air filter and air filter adapter allows for greater airflow and improved performance.  Also provides cleaner air for improved engine and carburetor life. Fits 47cc-49cc 2 stroke engines.
For use with this carburetor 

Includes:
Air Filter Adapter
High Performance Air filter

Air Filter Adapter Specifications:
Total Diameter: 1.75 inch or 44 mm
Center Diameter: .5 inch or 13 mm
Bolt Hole Spacing: 1.5 inch or 41 mm
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High Performance Air filter Specifications:
Product Style: Round Tapered (cone) Universal Air Filter
Base Outside Diameter: 2.91 in (74 mm)
Flange Inside Diameter: 1.69 in (45 mm)
Flange Length: 0.86 in (22 mm)
Flange Type: Centered
Height: 1.37 in (35 mm)
Top Outside Diameter: 2 in (51 mm)
Top Material/Finish: Metal/Paint
Filter Re-Oiling Amount: 0.26 oz (8 ml)
Weight: 0.25 lb (4.1oz)