These button housings are handmade by me in my wood shop and I typically use maple, pine, walnut, acacia or maybe even a combination of a couple types. They are shaped to follow the contour of a mid-range zoom lens (70-200 mm) and have a male mono plug for using with Pocket Wizard systems. They attach to the lens via an adjustable velcro strap that wraps around the zoom ring or the adjacent collar (as shown). The button, which comes fastened within the wood housing attaches to the strap and can be re-positioned quickly to what is most comfortable to you.