Item #71302 - HE   This Heat Exchanger is available in two sizes. The smaller heat Exchanger is 275 mm (L) and 64mm (W) at the widest part, and the cylinder diameter is 37mm.    The Big Boy Heat Exchanger is 434mm (L) and 105mm (W) at the widest part, and the cylinder diameter is 59mm. Important shipping information: This product in 1/16 & 1/14 or multiples of this product 1/25 - 1/24 will not fit into a (Small Box) shipping box. If you select a small shipping box for this product we do not guarantee that they will arrive undamaged. We will not replace any damaged products if an inappropriate shipping box has been selected. Choose wisely....