EARFOAMS are replacement foam tips for the ISOLATE range of earplugs. Each pair of ISOLATE and ISOLATE MiNi come with a pair of each size for you to try first. Once you know the size that fits best then purchase more. When trying always start with the smallest and work up, bigger foams doesn't equal better results. The opposite is true! When buying more EARFOAMS you first need to identify if you have ISOLATE MiNi or ISOLATE earplugs as the foams are not compatible with the two different sizes! Then the size of EARFOAMS you are using is determined by the colour of the centre plastic tube used to lock the foam onto the earplug. The metal earplug is 7mm wide Blue = Extra Small (Blue is only available for ISOLATE MiNi) Green = Small Orange = Medium ISOLATE Earplugs require ISOLATE Earfoams. The metal earplug is 8.5mm wide Green = Small Orange = Medium Red = Large (Red if only available for ISOLATE) Each pack of replacement foams includes 3 Pairs of the same size. For a more detail review of the size difference please visit the size guide page. ISOLATE EARFOAMS and ISOLATE MiNi EARFOAMS are NOT compatible or interchangeable. EARFOAMS are designed to only work with ISOLATE Earplugs and not other brands or types of earplugs.