This filter features DNA's Round Design.Installation of the filter is very easy, simply follow the information that can be found in the BMW workshop manual.The filtering efficiency is extremely high at 98-99% filtering efficiency, with 4 layers of DNA Cotton.This DNA filter is designed as a High flow filter for road use.Compatible with:R 850 R 1995-2006R850 GS 1993-2006R 1100 GS ABS 1993-1999R 1100 GS 1993-2006R 1100 R 1994-2001R 1100 R ABS 1995-2000R 1100 RS ABS 1993-2001R 1100 RS Special Edition 1994-1995R 1100 RSL ABS 1994-1997R 1100 RSL ABS Special Edition 1994-1995R 1100 RT 1996-1998R 1100 RT ABS 1996-2001R 1100 RA/S ABS 1995R 1150 GS 1998-2003R 1150 R 2001-2006R 1150 RT 2001-2005R 1150 GS Adventure 2002-2005R 1150 R Rockster 2004-2006