Dear buyers, we want to provide you with the most full information about your order so we combined several descriptions from different sources below. Some information could have duplicates, sorry for inconveniences.Flat slide design helps create a smooth bore effect, increasing air flow Significant performance improvements over older round slide carbs Great throttle response because of more precise fuel metering All are center-pull style throttle, unless noted by footnote Jetting may need to be changed per application Made in Japan. Square-type slide carburetors have increased airflow metering at low engine speeds. We are always happy to help you. Return Address: Do not use sender's address as a return address. All items MUST be in their original condition, not worn or altered. If the order that arrives is damaged, let us know and send photos. Also please make sure that the photo shows the part number of the item. Please make sure that you opened the Return request.