03+ Nissan 350Z/G35 Strup Test Pipes Stainless steel test pipes. T-304 #1 grade stainless steel tubing, polished to a bright luster. 2 1/2” mandrel bent tubing X .065 wall thickness. Flange is 3/8” thick stainless steel, TIG welded construction. Provides 8-10 horsepower gains. FREE SHIPPING ON ALL STRUP PRODUCTS!