You'll need the following to set up a fall protection system

An Anchorage Point must be capable of supporting 5000 lbs. per worker attached. Our six-foot cross-arm strap made of polyester webbing can be wrapped around beams and other structures to form a secure anchorage.

A Vertical Dropline with a minimum tensile strength of 5400 lbs., and secured to an anchorage point that is independent of the work platform.

A Full-body Harness so that in event of a free fall, the shock load is equally distributed to the body, as compared to just around the waist when only a safety belt is worn.

A Lanyard that absorbs shock and holds the free fall to six feet or less.

A Rope Grab lets a worker move up and down the drop line for freedom of movement, yet locks instantly when activated by a fall.

OSHA does not allow body belts as fall arrest in construction!
If you are participating in construction as part of your business, you should know that body belts cannot be used for fall arrest, only positioning.  If you work in agriculture or manufacturing, use of body belts is not recommended - you could be cited by OSHA under the general duty clause, or a worker could be seriously injured. Body belts can be used to keep a person from reaching the edge when working on heights. They cannot be used to catch someone who is falling. A full-body harness must be used instead. Full-body harnesses distribute the weight during impact. With body belts, all of the energy from falling is absorbed around the person's midsection, which can result in injuries.