Check this image please https://imgur.com/mkp36Jw . Is this equipment proper for a chest builder ? Which chest parts will improve and how much should someone do this?
If one is quite old, and need support, or the person is recovering from serious injury... For normal human being - pushups are better option.
To me it looks like a bit older tool that is sold in TV shops. Or maybe that is not older, but just real one? Anyway - I don't believe in it. Specially because there are great exercises like pushups, planks, or burpees.
According to muscle groups. Not sure if that really works like that, but I expect that lower catch is for training lower chest, and higher / wider - for upper chest. Triceps is also activated. When you do pushups, with elbows close to the body deltoids are also built. With this kind of equipment load is highly limited, so I don't expect that effect.