There is a front and back component and the front includes a circular pop-out sticker for the home button. I suppose you could choose to use, or not, if you want to retain the feel of the original glossy button.
In addition to providing aesthetic appeal, the skins can provide a degree of protection. I wish I had a Lastu skin earlier, as my iPhone fell and developed a hairline fracture. It's not on the touchscreen part, but close to the earpiece, so by adding the skin, I was able to cover it up and possibly avoid further damage, while adding some old school style.
Unlike competing solutions, these are made from real wood and the makers support sustainable projects, so they help plant a tree in Zambia for every two Lastu products sold!