Keeper EPDM rubber compound is engineered to perform better than standard rubber in straps. Unlike straps manufactured from cheap rubber, these straps will not crack, rot or lose rebound qualities and Keeper rubber remains nonbrittle in temperatures as low as -40 deg F. Each strap in this pack of 10 resists damage by sunlight, ozone and demanding weather. Strength and durability are ensured by zinc plated, steel hooks that will not rust, corrode or break as easily as other straps, making Keeper EPDM Rubber Straps the best choice whenever you need a reliable strap.Zinc-plated, strong steel hooks will not bend, break or rust under normal use