The reserve is folded to fit inside a deployment bag. The deployment bag is secured with a locking stow (a section of the lines pulled through an elastic loop) that will slide out easily when the reserve is thrown. The lines of a reserve are attached to a bridle, which is attached to another bridle that is connected to your harness at the shoulders. A metal link or a girth hitch is used to connect the reserve bridle to the harness bridle and this connection should be secured against movement or loosening, respectively. Once the reserve is connected to the harness, it is placed in the reserve container located on the harness.
Harnesses vary in the location of their reserve containers; generally they are front, side, back, or rear mounted. The bridles are secured in a routing system on the harness to keep them in place and, hopefully, UV protected. A handle is attached to the deployment bag, and is used to extract the bag from the harness. On the handle will be either one or two pins, used to secure the harness container. The pins, usually curved, are designed to release with little effort, making it imperative for a pilot to guard against accidental deployment. Reserve deployments close to the ground have led to serious injury and should be a consideration, when carrying a reserve parachute. You should become very familiar with your reserve system, so that you can take the deployment bag out and put it back, in case it gets pulled out accidentally (on the ground) or, you need to take it out to be repacked.