A connection device for connecting two structural components is comprising a retaining member in a first structural component and a fixing member for insertion in a second structural component for connecting engagement with the retaining member thereby holding the two structural components together. The fixing member comprises a plug member having a first end and a second end, the the first end comprising an undercut head for insertion in and retaining engagement with the retaining member. The plug member is comprising a member for engagement with the second structural component.