Meet the Sullivan Supply Black Heat Cattle Neck Sweat. This double-stretch, closed cell SBR copolymer neoprene black sweating material has been scientifically proven after hours of research to be the best material to reach maximum sweating potential for cattle. The bonding of this advanced micro fiber neoprene with the velvet knitted fabric creates more sweating results than any material we have ever tested. The No-Fray design features fabric binding sewn around the outer edges to prevent tearing and to add strength. Velcro is permanently sewn in place for your convenience. Dramatic results in just 3 to 5 days!