Pac Safe travelsafe 100
This is the link for the lock
There are two pairs of zippers. The main compartment as well as the smaller front one. If you go to the REI link and mouseover the zipper you will see that there is a hole in each zipper.
We strung the retractable cable through each hole and then around the post of the palapa. The cable is 2.4mm / 0.1in diameter high-tensile stainless steel wire wrapped in this plastic to make the surface smooth.
No way anyone is going to get through that without someone on the beach seeing it.