They are bright and work great. I get many many flights before recharging. I just Velcro them on left and right sides of motor mount rails and on top rear of copter.
Actually I was surprised on how bright the strobes are, ordered 2 more sets for my H and my XXX-830 copters.
But for the typhoon H i went with the round units with connection wire to single cell I can slid into each landing leg. They are perfect size for the foam landing skids.