Review on Tilos 3Mm Waterproof Neoprene Fin Socks - Ideal For Scuba Diving, Snorkeling, Swimming, Watersports, Hiking & More! by John Gray

Great for use in rocket fins. Thick enough to provide cushion, but not so thick that they effect the fit of your fin. They are low cut, so expect a little bit of heel slip while using, but not so much that you need to reset the sock or fin. I wear a size 8 (men's) shoe, bought a size 7 (men's) sock, fits perfect. Took away 1 star just for the inherent heel slip that comes with low cut socks, but they're much easier to put on/ take off compared to higher cut socks