These earmuff cups comply with UNE-EN 20352-3 SNR-23dB. They are perfect adjust to every the safety helmets. High performance hearing protection. They are particularly designed to be used in industrial, gardening and DIY works. They are directly connected to every type of safety helmets with no need for adaptor. The inner side of these cups have a large space which makes reduce humidity and heat buildup. The new technology of their cushions has a very effective acoustic insulation and a very reliable protection. Red coloured.