Mosquitoes are a common enemy in a lot of parts of the world, spreading both irritation and diseases. Most common products used to combat mosquitoes use various chemicals to repelor attract and kill them. This master thesis at Luleå University of Technology during the spring of 2024 was conducted in collaboration with Ozoneair to give an insight in how this problem canbe solved sustainable and based in user centered design. This project investigated how ultrasound can be used to repel mosquitoes in a more sustainable manner. With a user centered design approach the project was conducted with constant feedback and interviews from users to enhance the result. This spanned from interviewing users during the context immersion phase to investigate their needs and issues with current products to user testing prototypes. Research on ultrasound was investigated to find theory on how it can be used against mosquitoes and what has been tested and showed promising results. By using several creative and iterative methods several concepts were created and improved until a final result was presented. The final result is presented in a physical 1:1 visual prototype as well digital renders over components and technical aspects. The result is a portable battery powered product that is adjusted to the users needs both in terms of appearance and use case.