Yep, need the grab bag for the extra parts...costs about $20. Have fun!

From above: "the key is .8 x 30 mm machine screw and extra nut purchased at your local hardware store for ~$1." This is the size that fits the GoPro "holes." Hope this helps!

Harry, first of all, a phenomenal app set! Have OMP belts in my car and had used the OMP app not realizing that LapTimer Pro had video capability until just recently. Now I've made the switch and how beautiful it is to overlay the video so easily inside the app! As a GoPro user with several mounts i...