Most gutter guards work to a degree. Some very limited. Apart from functionality, one of the most important things you should think about is the life of the guard. Plastics are not made for Australian conditions as they expand and contract. This causes them to crack, bubble and most are highly flammable. We remove most plastic guards within 5-6 years. Steel is the best but needs to be a quality Australian Made steel in order to be better resist deterioration and rusting.