The antenna elements are made from aluminum tubing.
The reflective and directive elements are 3/8" ID tubing. The reflector is 43 1/2" long, and the director is 35 1/4".
The driven element is 1/2" tubing and is 41" long, including the 3/4" gap in the middle. The fact that the driven element is bigger tubing is a result of what I had in the scrap pile and not part of a grand design.
The elements are spaced so there is 10 1/4" from the front director to the driven element. The reflective element is an additional 18 1/2" behind the driving element.
The feed area has a fibreglass rod about 8" long that extends into each side. Each driven element is cut with a hacksaw to make slots, and drilled for the stainless steel hardware bolts. The coax lugs and bolts are tightened down and are not loosened or removed when collapsing the antenna. There is 3/4" spacing between the elements to match the boom size.
The reflective and directive elements are marked in the center so they can be placed easily when assembling the antenna. Otherwise they are just pieces of tubing cut to length.