this exercise really helps you target three muscles at once. great for people with push/pull/legs routine to include in their push day. this exercise is normally good to do after you isolate each of those three muscles(shoulder, chest, and triceps) in order to fatigue them to the full extent.
like normal chest press, the angle of the bench affects which part of your chest you target more, but also, the more upright you sit, the more triceps activation you have, and the more you angle it down, the more front delts you activate. do not forget to squeeze the dumbbells together for perfect chest activation.
also, make sure you do not bend your wrist forward or back and try to keep it straight. although you are not going to be able to lift as heavy as when you do a normal bench press, still it could be harmful to your wrist to bend it backward or forward.