1. Corrosion Resistance, High Hardness 304 stainless steel rings made of high quality raw materials. No rust, corrosion resistance, high hardness, non-toxic and pollution-free environment.^ 2. Safe Sturdy Heavy duty commercial grade swing hooks are designed for use by children and adults, and designed for residential use at a rating of 450kg , they are secure.^ 3. Easy to install We have pre-drilled two holes for bolting to wood or concrete beams 4. Indoor and outdoor use For indoor and outdoor use, applicable to concrete ceilings and wooden beams, and can be used more widely. Optimal use as a wall hook for sling trainer, suspension trainer, rotate chairs, hit bags or hang any heavy object on a hanging rack.^ The set includes: 2 M5 long oval door buckles, 2 M5 snap hooks, 4 4*25 self-tapping screws