ALPHA 2 RK501
The Quadrifoglio is originally designed by Bandini Buti for Ultravox, a company in Italy mainly producing radios. The Quadrifoglio radio was introduced in 1968. The radio comes in a white version as well as in red/orange.
There is a lot of confusion on the producer/designer. The radio was namely also produced by Siemens. Siemens most likely produced this radio for the German market under the name Alpha 2 RK501. On the pictures displayed, you will clearly see the logo of Siemens. However, many radios still have the text Ultravox displayed on the radio.
Many people think that the radio was produced by Mario Bellini for Siemens.
Several sources however point in the direction that Bandini Buti is the designer of this radio. In Italian design literature (Abitare 1971/1972 and Mettiamo su casa insieme), Bandini Buti is mentioned as the designer. In addition, the office from Mario Bellini confirmed that Bellini is not the designer.
If you look carefully you should be able to find this radio priced around 150€, still in a good condition. Some people tend to ask however a higher price. I have seen a few radios that were sold around 125€, so if you have some patience you might be lucky!
Source pictures: ACA Auctions
Text partly based on information from BB Plastics