*Worlds toughest security chain!*The only 19mm quadruple tempered security chain!*Case hardened (not through hardened)*Carbon manganese alloy steel enhanced with boron.*Thatcham Approved.*Impervious to hand bolt cropper attacks!*Hacksaws useless!*Zinc plated with gold passivation for maximum corrosion protection.*Almax's long link system allows:--You to lock your chain off tight, stopping sledge, wedge and freeze attacks dead in their tracks!-Multiple Almax chains to be secured with just the one lock!