JUST GOT THE HERO3 SILVER AND IT CAME WITH A CURVE AND A FLAT ADHESIVE MOUNT. lOOKING AT MY HELMETS VENTS, IF I PUT THE MOUNT IN THE MIDDLE I WILL BE STICKING THE BASE OF THE MOUNT ACROSS A VENT WITH MINIMAL CONTACT AREA ON EACH SIDE OF THE VENT. iS THIS WHY THEY SELL A MOUNTING STRAP...