Sleeep Flex has been designed following feedback from some of our customers. We discovered that there was a need for an earplug that reduces background noise and irritating sounds to a more manageable level whilst also being so comfy that they could be worn for long periods of time by more delicate ears. Sleeep Flex (with small tips) measures 26mm in length and 11mm in width. Sleeep Flex comes complete with Extra Small, Small and Medium Earfoams and a Flare carry pouch. Replacement Earfoams are available separately in packs of three pairs on Amazon. Small = 9mm diameter, Small = 11mm diameter, Medium = 13mm diameter. Sleeep Earfoams generally last about 6-8 weeks depending on how they are handled, used, and your body chemistry (earwax, oils, etc.). Naturally, increased use will decrease their life. To ensure that the Earfoams last as long as possible, we would recommend that you follow our fitting guide in the product images and clean them with a damp cloth - do not submerge in water or clean with alcohol. It is important that Earfoams are regularly inspected for serviceability and are maintained in accordance with our instructions. Be sure to replace your Earfoams when they start to "flake", tear, or lose their memory foam properties (e.g. the foam expands quickly rather than slowly).