All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Setting up a project for mobile phone headsets and accessories is Islamically permissible, whether the project is related to manufacturing, or buying and selling, because these manufactured devices are permissible in and of themselves, and they are not originally intended for a forbidden purpose.
For more benefit, please refer to Fatwa 432466.
Allah knows best.