A 50mm outside diameter alloy bend, one of the mainstream sizes for intercooler and intake fabrication. It suits moderate boost applications and intake tracts on small to mid-capacity engines, where it flows well without demanding the space a 63mm run needs. Cut the bend to length, deburr the ends and join with silicone couplers and clamps to build a route that clears the engine, chassis rails and cooling pack. If your system runs meaningful boost, use clamps rated for the job and leave enough straight length at each end for the coupler to grip properly, since a joint made on a curve is where charge pipes usually blow off.