Phonak Serenity Choice Comfort reusable earplugs are designed for everyday use to improve concentration without causing irritation. The earplugs reduce all types of background noise and can be used in any situations, such as open office environments, traffic noise, loud colleagues, irritating sounds in libraries. Office filters reduce sound for all frequency, but you will always hear conversation if you choose to and will never feel isolated. The earplugs filters provide an open air passage to the ear keeping the ears ventilated at all times and minimising occlusion effect. The earplugs include hypoallergenic ear tips that are made from medical grade TPE. The product is available in small(5-10mm), medium(6-11mm) and large size(7-12mm) and includes 1 year warranty.