Ideal for heavy-duty strapping jobs these 100% Natural rubber tarp straps available in 5 sizes including 9″ , 15″ , 21″ , 31″ and 41″ straps. The straps are made out of an ethylene propylene diene monomer (EPDM) rubber that helps prevent cracking, rotting, or lose of rebounding for enhanced durability. Straps come with crimped S-hooks to keep them firmly attached, preventing the loss of hooks.