If there is a compatibility problem with Bluetooth 5.0 and Bluetooth 4.0, it is neceary to install the driver-program. Please send the email to the customer service, and the customer service will send it to you as soon as poible. Dear friend, if you do not receive the product, or there is a compatibility problem, please communicate with the customer service first, and the customer service will provide you with a solution as soon as poible. You will usually be offered a refund without you having to initiate a dispute. Customer service can automatically refund. Product A: USB Bluetooth 5.0 Adapter SpecificationsItem Name: V5 Bluetooth 5.0 AdapterInterface: USB 2.0Transfer rate: Max 24MbpsBluetooth Version: Bluetooth V5.0Frequency Band: 2.400-2.480GHzColor: BlackItem Size: 21x16x5 mmOperation System: Windows 7/ 8/ 10/ Vista/ XP/ 2000/ 98/ Me etc.Low-power selectable 1.2 to 3.6 VI/O.Supporting multiple languages.Compatible with Bluetooth v1.2/2.0/2.1/3.0/4.0Supporting multiple languages. Product B: USB Bluetooth 4.0 Adapter Features:1. Fits for bluetooth 4.0 standard, dual mode transmiion.2. Stable and strong signal, low power consumption.3. Built-in antenna, up to 20M long distance transmiion.4. 3Mbps transmiion rate, suitable for files and music transmiion.5. Backwards compatible with for bluetooth 2.0, 2.1, 3.0 standard.6. High speed, free drive, plug and play, stable and secure.7. For desktop: easy to acce network with this product.Specifications:Type:USB for bluetooth adapterInterface:USB 2.0Working frequency:50MHzMaterial:Plastic, metalColor:BlackTransmiion rate:3MbpsFor bluetooth standard:4.0Operation systems:for Windows XP/7/8/10Effective semidiameter:10MPlug and play:Support