Bluetooth 4.0 and 3.0 compatibility

I Have a first gen iPad mini with Bluetooth 4.0 and I wanted to get a Bluetooth audio receiver for my iPad to connect to so I cam listen through my headset without wires, but uses 3.0 technology and I was wondering if it would work before I buy it

ebay.com/itm/NEW-Bluetooth-V3-0-Audio-Music-Receiver-3-5mm-Adapter-Handsfree-Car -AUX-Speaker-/261621173776?pt=US_USB_Bluetooth_Adapters_Dongles&hash=item3ce9d64 e10

not sure if I'm allowed to put links in but that's what I was gonna buy and inwas hoping someone that knows about Bluetooth could help me