I heard a fellow skydiver talking about it, I ask him about it, he told me the best gadget he has bought for skydiving. I bought my on a special even before i bought my helmet, so i can presuade myself to by helmet for it. I used last week and i felt in love with it. its great. You can concentrate more on the skydive, it doesn't matter what you like to do up there, Freefly, RW, ETC. Its accurate and loud.
Cielos Azules
Enjoy