Round reflectors for trailers, reflective rounds for gate posts, all our reflectors are ECE approved. Specifications: Diameter: 83 mm, screw length: 20 mm, one mounting hole. Material: PC UV lens Lens color: red< br/> Installation method: Screw fixing Package includes: 8 round reflectors 8 stainless steel bolts and nuts Each round safety reflector matches a set of nuts and bolts. Gives you safe riding protection.