Radio base stations contain equipment which enables the use of cell phones all around the world. ERICSSON is developing these stations and everything connected to the area, such as electronics, software and hardware. In a new project ERICSSON plans to make their hardware modular, to satisfy all their customers around the world even if their preferences differ. The task that was given to us was to develop a modular locking system to the radio base station cabinets.The concept was developed in an integrated working process that focused on a user centered final product. The process included the definition of the problem, preliminary studies of areas which are connected to the problem and a summary of the demands that the customers mediated in a list of requirements. The idea generation generated lots of ideas that later on were developed into different concepts. The concepts were evaluated before the final decision was made together with ERICSSON.The final product is a lifting handle connected to a rod and latch system, which already existed. A new mechanical function was created to make the new handle function with the old system. The locking system is modular and it is possible to choose which way to lock the handle, with a cylinder lock or a padlock. Only one module, the cylinder in the middle, needs to be switched to get the other solution. The other parts are the same; this makes the product modular. The lift handle is an entire new design, developed in the project.