BMW F8X M2C M3 M4 Intake system EMBLEM Bend: 135 degree Inner diameter do88 kit219S Bend: 135 degree Inner diameter 1 (mm): 13 mm Inner diameter 2 (mm): 16 mm Inner diameter 1 (inch): 1 2 inch Inner diameter 2 (inch): 5 8 inch Leg length (see picture): 102 mm Color: Black Wall thickness: 4 mm Temperature range: 40 to +180 degreeC Outer diameter 1: 21 mm Outer diameter 2: 24 mm Reinforcement: 3 layers Material: High quality silicone rubber polyester fabric Reference: 7524176 This test was performed on our M3 with a BootMod3 Stage 1 (93) tune We found that we could use large double cone BMC air filters with large filtering area for high flow not just when new (small filters starts to flow worse after short usage)