AEMs recirculation style pump offers improved performance, reliability and a much smoother, quieter operation when compared to older switched style pumps. With the use of a new internal bypass design, AEMs upgraded pump eliminates the erratic on and off switching/pulsing and ensures consistent fluid delivery for optimum performance. With durability and reliability in mind, AEM has designed the pump with a Santoprene diaphragm and EPDM seals to withstand the harshest of alcohol mixes.