The Accessory Pro® 24 inch Stainless Steel Tether Lanyard compatible with all GoPro® cameras Price: $9.99 (as of 02/06/2019 15:47 PST- Details)

The Accessory Pro® brand product, made to be used with GoPro® cameras.
Saltwater is ok and will not harm this cable.
Attaches around the thumb screw, doesn’t slip off.

Usually ships in 1-2 business days