Body Sculpture is one of the world Is leading manufacturers of exercise equipment and accessories. 

A weightlifting belt has two main purposes. It reduces stress on the lower back while the person is lifting in an upright position - and it prevents back hyperextension during overhead lifts. A belt reduces low back stress by compressing the contents of the abdominal cavity.

If you Are hitting machine weights all workout long, you do NOT need a weight lifting belt. Even athletes training bodyweight movements or dumbbell conditioning won't find much benefit with a belt. Belts should only be needed when moving large amounts of weight on a barbell. Squat - deadlift -  push press - etc.