They should fit the handlebars of all bicycles, some motorbikes, and also to the helm bars on yachts.
You'll be able to talk and hear through them without a problem
You can get great video with your front-facing camera. The bike mount attachment means that there is no room to fit a lens window on the back of this case, so you cannot use a rear-facing iSight camera. Sorry!
Your touchscreen will work normally
They're not just 100% waterproof, they'll protect your phone from dust, dirt and sand too
You won't necessarily have to buy a new one when you upgrade your phone, because it's a generic rather than a form-fit case (unlike a hard case, it's not tailored to a specific device).
Fits phones as large as I-phone 10 and 11 with modest cases on!
It features a total length of 6" and a circumference of 8", making it suitable for thicker phones like the T-Mobile G2 or even certain GPS units like the Satmap Active 10. With an IPX8 rating, the pack can be submerged at depths up to 30 feet for as long as 30 minutes, plus it will protect from sand, mud, dirt and mitigate against potential sources of scratches and damage. It mounts on bicycle handlebars or other tubular structures - even the helm of a boat.