Tunnel supporting leg includes elongate articles (18), it is provided with thread segment (22) on fixed area (20), support region (24) element, in use, part cover supporting member component (12) associated tunnel can be fixed, there are the first attachment structure (28) with connecting plate (26), second attachment structure (30), wherein the longitudinal axis of the first and second attachment versions (28,30), which is spaced apart elongate articles (18), passes through different spacing.
