3 Strand 100% Nylon Head Rope 31' 3/8" True XXS, XS, S, MS MACH3HD BEST SELLER! The Mach III, designed with Speed Williams, is a 100% nylon rope that is small and light with a lot of tip. The size and speed make it perfect for today's short horned cattle with enough body to stay open for big horns. Fast Back Ropes was founded in 1995 on traditional family values and personalized customer service while making high quality nylon and poly ropes. Fast Back brand is renowned internationally for ropes with the most consistent body and feel.