Before they even put the Xbox logo on the button. I have not seen any of these unbranded wireless Radon for sale on the net at all. Rare opportunity to own this piece of historic Microsoft Xbox History. I tested this with both batteries and a Microsoft rechargeable battery pack and it works flawlessly.
See the pictures for more details. Here is a video about this model of controller.
The item "Xbox 360 Wireless PROTOTYPE Controller Radon DV1 EXTREMELY RARE" is in sale since Wednesday, February 19, 2020. This item is in the category "Video Games & Consoles\Video Game Accessories\Controllers & Attachments".The seller is "gamegurus206" and is located in Seattle, Washington. This item can be shipped to United States.