This neck mounted magnetic phone holder appears to have been designed for the petite. My head barely fits through the neck holder hole, although I will admit, I do have a large head. There is a release for the hard, bendy part of the neck hole, so you can use that to get it around your neck if you need it. The chest strap is very small. I have a 36" rib cage and wear a men's large shirt and the strap is probably 6" too short. You don't necessarily need to use the chest strap but it does help stabilize the holder.Those are the negatives but there are a lot of positives as well. The assembly was very intuitive. I was able to put it together without using the included directions. You can attach the phone to the holder via a magnet (either a magnetic ring built in the phone/case or you can attach an included magnetic ring) or via a traditional clamping method. The holder has a lot of available positions allowing it to be used to film your point of view or to watch videos on your phone. Without having an adequately sized chest strap, I wouldn't feel comfortable using this in any sort of fast paced activity since the strap is needed to really hold it in place.