Particulate respirators are the simplest, least expensive, and least protective of the respirator types available. These respirators only protect against particles. They do not protect against chemicals, gases, or vapors, and are intended only for low hazard levels.
A factory tow package usually includes heavy duty rear shocks/springs and an auxiliary transmission cooler in addition to the tow hardware itself, and sometimes they include a full size spare tire too. When a dealer installs it they just put on the hitch and wiring plug.
Towing capacity refers to the maximum weight your vehicle is able to pull while towing -- i.e. the weight of a trailer, a boat, or another vehicle that you plan to tow. Although towing typically involves pulling weight in a trailer behind a vehicle on the road, towing can involve tractors and waterborne vessels.