Is it permissible to sell a descrambling card for explicit channels if the seller stipulates that it must be bought with the device?

It is not permissible to buy, sell, or gift devices used for unlawful purposes, as this constitutes aiding in sin and transgression. Such devices must be destroyed, and whoever propagates them bears the sin of everyone who deviates because of them; they are an ongoing evil. Jarir ibn Abdullah narrated that the Messenger of Allah, peace and blessings be upon him, said: "Whoever introduces a good practice in Islam will have the reward for it and the reward of those who act upon it after him, without any decrease in their rewards. And whoever introduces a bad practice in Islam will bear the burden of sin for it and the burden of sin of those who act upon it after him, without any decrease in their burdens." One must repent to Allah, destroy these devices, and use their expertise to spread good and prevent evil.