The report describes the graduation project done for Lifesafety Products B.V., otherwise known as Lifehammer. The company has a problem with the attachment systems of their emergency hammers. These hammers are used to break car glass in emergencies. The most commonly known use case in the Netherlands is when one ends up trapped in a car submerged in water. Due to the limitations of car interiors regarding suitable locations, a new spring-loaded hammer was developed, which is much smaller than the existing hammers of Lifehammer. The product is to be installed on seat belt receivers, which are universally present in cars. A working, 3D printed prototype was made which was capable of breaking tempered glass, which car (side) windows are made of. Some ergonomic problems were encountered during user tests, as the novel product was not easily recognised.