Hi Jack
I picked up a length of Aluminium tube, cut it at 45 deg at the length I wanted the pipes then polished them up, as they are heavy wall they went straight on where the originals came off with a dab of glue. as mentioned they are 10mm dia. 12mm was too big but would look good on a more custom build, I was looking at putting a slight bend at the top to curve them out for a more traditional look but the straight ones suit my truck.