Dual-Density liner - Expanded. PolyPropylene (EPP) and comfort foams. Strategically located comfort foam pads eliminate pressure points and grip the head. Great comfort and a snug fit. 3 distinct shells (S/M/L) ensure an optimal fit and maximal ventilation. Dual ridge crown offers protection against impacts. Ergo translucent ear covers. Tool-free adjustment clips - Allow you to simply flip up the clips, adjust the sizing, and push the clips back down for a quick, easy, performance fit. CSA, HECC, CE Certified. Compatible with the Bauer 8500, 8000 and 4000 cages.