Original RS (C7) intake airbox.  Can be fitted to A6 / A7 3.0BI-TDI engines and as a S6/S7 4.0T upgrade.  Recommended to use with Revo filter and Darkside hose. 
But its useful with stock BI-TDI filters and hoses also.
ATTENTION:  Do not try to use RS filter on BI-TDI engines, cause RS filters upper hole is wider than BI-TDI maf neck,  it will suck dirt to engine!