If you are looking to reduce fuel consumption and improve throttle response, you can`t go far wrong with a boost bottle. The advantage is that the air-fuel mixture is not fed back through the carb a second or third time when off the throttle but rather through the boost bottle which is mounted between carb and the membrane. This also prevents the mixture from becoming over-rich. When you crack the throttle the stored-up mixture is fed in and acts like a little turbo boost - hence boost bottle. Delivery as pictured.