Catch impurities in air to prolong the engine Life.Add more horsepower and ensure better mileage and engine performance. Come with clamp to steady the interface.Environmental protection and safety. Material: metal & rubber. Inside diameter: 39mm Note: Please measure your carburetor’s mouth OD in order to get correct measurement. Product description Fitment: Most motorcycle, scooter, minibike, ATV (Please check the size before buying). Packaging List: 1 X Motorcycle Air Filter Note: NO Retail Box. Packed Safely in Bubble Bag.