What is the ruling on selling and installing antennas, receivers, and flash drives?

The ruling on selling and installing antennas, receivers, flash drives, and similar devices varies according to the condition of the buyer or user. If you know or predominantly believe that they will use it for unlawful purposes, then it is not permissible for you to sell it to them. If you do not know or predominantly believe anything specific, do not sell it to them, because most people use such devices for unlawful purposes. Whoever is unable to control the sale and installation of these devices according to what has been mentioned, then it is not permissible for him to continue in this line of work, because it is assisting in sin and aggression.