Dynamic's High-Impact Bumper Plates are made from quality crumb rubber, giving them the softer bounce preferred by some trainers, gym owners and competitive lifters. They are made with recycled vulcanized rubber, and feature stainless steel collars for long life and durability. The collars are inset from the outer edge of the plate, which maximizes space with multiple plates on the bar. These quality bumpers are IWF standard 17.7" / 450mm in diameter and are perfect for executing technical lifts like the snatch, clean and jerk and dead lift. A high-performance, economical solution for any weight room or training facility; much quieter than cast-iron plates, with softer bounce than standard bumper plates.