Hubboards Bodyboard Fin Sock with Cinch Lock Tether The Hubboards fin sock provides extra protection and comfort for your feet and ankles when wearing swim fins. The new sock lock tether loops around the fin strap and over the top of your foot to help keep your swim fins secured to your feet. Hubboards fin sock are reccomended for people with sensitive feet, loose-fitting swimfins, or for people that are planning on surfing for extended periods of time. Features:2MM NeopreneLow-cut Closed heelSock lock tetherAdjustable cinch fin tether