Old rubber ball with modified LED lamp(well, for this pic I didn't insert it, but it's there, yes). It'll be attached with a dog lead hidden in the top element.
You can check out how I throw it here: https://www.youtube.com/watch?v=gWadTurmhgY&list=PLv43-Nr2vQsGYYSNGKIvYvEkl__RHoEsI
Works out on the finished rod as well. I already tested it and it doesn't damage the wings on top at all.