I have a Starline GPS-3X lap transponder for sale... I am at Houston...
It does not need charged as it comes with hard wire to battery terminals, USB port as well with fuse.
$125 obo

Call and or text me, as I will not think to check this at track.
81seven- 77three seven14seven

P.S.
I am driving to MSRH now and will arrive late tonight.
Thanks Walter, BOD, and the ones who are working the 24 hr gates at Houston. M. Thank you!