I have 3 R.E.S. that were using the Zoo-Med floating Dock (large) and it worked well when they were small; the problem was that they were too big/heavy to have 2 on at the same time. They would sink due to their weight. The turtle topper assembles easily, and can support all 3 turtles at once, albeit cramped (it's 2 LARGE females, and a medium male). Now that several can bask at once, they are finally shedding properly. Their color is improving, their shell is improving, even their demeanor is improving. My only recommendation is to use double-sided tape between the base and the clear cover; otherwise they can push the top off and hop out. I am very pleased with this product.