Fin tethers work as a preventative to your fin coming off rather than a solution for saving it once it has actually come off. The fin tether is an old school concept which has been recently reintroduced to the bodyboarding market. The fin tether uses neoprene which runs around the back of the fin and offers comfort across the back strap of the fin. Often this neoprene can fill out the fin an extra foot size or so, so always be weary when buying fin tethers in that they can add additional size to your foot. Once the neoprene has wrapped the back of the---- fin, there's a strap across the top of the foot pocket which runs slightly higher than the foot pocket of a fin. This extra height means there's little to no room for your foot to be forced out of the pocket. Which will save your fin from coming off in bigger and more demanding waves and situations. Fin savers by comparison are less of a preventative and more of a solution to your fin coming off. Fin savers lasso around the back strap of your fin and then you use the velcro to tether the fin to your ankle. This way if your fin comes off in the water it's still going to be connected to your ankle. The fin saver is highly effective in keeping your fin close by should you wipe out on a big wave or find yourself in heavier situations. If you're travelling abroad or surfing some of the heavier conditions on offer in the bodyboarding world we will ALWAYS recommend you take either fin tethers or fin savers. Because if you lose your fin out there you might just not find it again. Think smart, think fin tethers or fin savers.