This is a holster for attaching a camera to the shoulder strap of a backpack. When you hang a camera using a neck strap, it can swing around and bump into things, or cause neck pain. However, using a shoulder holster in conjunction with a neck strap allows you to secure the camera firmly. It's also easy to release. I used to love using this when hiking. To remove the camera from the holster, pull the lever. To attach the camera to the holster, no special operation is required. What I liked about this product was that the tip of the holster is long, so even if the camera tries to tilt forward or backward while walking, the tip contacts the shoulder strap, preventing it from tilting. Also, when placing the camera on a table or other surface after removing it from the holster, you can bend the frame at the bottom of the quick release 180 degrees forward, so the lens tip doesn't touch the table. It attaches to the shoulder strap using a rubber band. The band is secured by inserting a rod into the two long, cylindrical holes at the end of the band. You can choose the length of the band by selecting which holes to use. The camera might gradually slide down if it's heavy (this isn't unique to this product), so I used a string to prevent it (the string is not included). The camera and quick-release plate are secured by tightening the screws using a coin or similar object.