Maradyne Texas Twister mechanical fans are constructed from a heavy-duty flexible blend of glass-filled nylon and thermoplastic elastomer. They offer an economical cooling option for any vehicle with using a 4-bolt water pump pulley. The fans have a maximum operating range of 8,000 rpm, and their lightweight design is perfect for weight-conscious racers. Maradyne Texas Twister mechanical fans are available in 14 to 18 in. diameters, so you can choose what's best for your specific application.