Phonak Serenity Choice Work reusable ear plugs are designed to protect your hearing by reducing noise levels in noisy working environments including those in farming, construction and mechanics. Hearing protection is required by health and safety in any situations where noise levels exceed 85dB. Earplugs reduce the sound level by 24 dB making it safe for 8 hours continuous use in any environment up to 109 dB. Combine it with earmuffs to double up the protection in very loud environments. Acoustic filters are fitted with advanced mesh technology to ensure that your ears remain well ventilated at all times and also minimises muffled sound to allow situational awareness and communication. The earplugs include hypoallergenic ear tips that are made from medical grade TPE. The product is available in small, medium or large size and includes 1 year warranty. Product dimensions small(5-10mm) ,medium(6-11mm), large(7-12mm).