Die Wethje is the OEM manufacturer for BMW and their CSL airbox. This airbox is a variant, by Die Wethje, for the S54 CSL setup. The exact purpose of this box is unknown. With the missing unfiltered portion it is a race style (similar to the Karbonius Race), but it lacks some of the details that the P54 airbox has. This box falls in the middle of the CSL and P54.
This is for the main airbox portion only. No other parts are included other than an OEM grade replacement BMW M Power sticker. What you see shown is what you get.
The overall condition of the airbox is excellent. The fit, finish, and quality is exactly what you would expect from an OEM manufacturer for BMW. Easily exceeding well known aftermarket brands.
Please note: This is a more rare variant that uses a flat edged unfiltered intake mount. It's possible that other styles of unfiltered intake pieces fit, but this will require owner effort to determine.
Die Wethje Sticker Details ZB Airbox CSL W2003BMWE46ABCarbon01 #023 2004 Production Date