Held in place by our powerful rare earth neodymium magnets with a pull strength of 37 kg, on industry standard 3 mm thick steel. For indoor and outdoor use. Suits any stable metal structure: steel posts, I-beams, star pickets, generators, hand rails, sea containers. Non-conductive polypropylene Hook-Head, 6mm bungee cord safety lanyard attached to a situational slider to suit different applications.