This is what I use, its just standard house hold electrical wire 12 ga insulated. With a hair tie (rubber band) to hold it in place.
https://www.mobileread.com/forums/showthread.php?t=96345
It works very well on the Jetbook Lite, because it has a battery compartment bump with 2 flat ends for the rubber band to "snug" the wires up too.
On a regular Jetbook I just slip the rubber band over the length of the jetbook to hold the wires in place, just missing the page turn buttons.
I really like being able to go hands free except for page turns.