The simple solution to roadside inflation. Thread the cartridge on, press it onto the valve, and air is in your tire. No-nonsense approach that you can count on to get you home in a pinch. - Aluminum body with rubber insulators - Spring regulated air flow - Light action spring - Hardened tool steel puncture pin In 1982 SILCA developed the first regulated CO2 inflator. As Claudio himself explained, 'Before EOLO, you had to turn the cartridge and pray!' Giving the user the ability to regulate the flow of gas into the tire was the key to widespread adoption of compressed gas for roadside use. EOLO IV builds on the SILCA tradition by dial design give the user perfect control of the flow into the tire. The full metal construction of the EOLO IV contains no plastic parts and is manufactured entirely from 6063 series aluminum and stainless steel. Hardened tool steel puncture pin is more than 2X the hardness of traditional puncture pins to ensure smooth operation in all conditions over many years.