>https://tehnoetic.com/tet-bt4 >Technoethical Nano Bluetooth 4.0 USB Adapter for GNU/Linux-libre >for GNU/Linux-libre >based on the CSR8510 integrated circuit >Price: €34 >aliexpress >bluetooth 4 CSR >free shipping >US 2.73/piece >for GNU/Linux-libre >Price: €34 >no bullshit >US 2.73/piece