These are balsa floats meant for a 5 to 7 pound plane, 60 size, more or less.
An alternate version is available with a 3/4″ x 15 inch spine to take the place of the plywood brackets. This spine is to be glued on top of the float. Your landing gear axles are then attached with nylon straps, and wheel collars are added to each side of the plywood spine to keep the floats from sliding sideways.
My parts are 98% of the original size. If you’re wondering why that is, it’s because the designer made the top and sides 36.25 inches long. If you look at most model planes, the parts tend to be just big enough to be cut out of a standard sheet of balsa wood. (Ever wonder why 36″ is such a common wingspan?) At standard size these floats would require me to jump to a 48 inch sheet for eight pieces, costing you a significant amount of money. At 98% the sides and top are just a hair under 36″, which of course saves you a significant amount of money!
When you build these floats, print the plan at 98%. Or better yet, save the money on printing and use the float top as a plan. The float tops are made in two halves. The kit for a pair of floats includes four halves, and the bulkhead locations are etched onto two of them. Select an etched half and a non etched half for each float. Join the two halves to make the top, then use a square to stick the bulkheads on, then add the keel and the stringers, and then the sides. Add the bottom sheeting, except where the landing gear anchors are located. Turn the float over and add the plywood landing gear anchors, gluing them to the bulkheads firmly. Then turn it back over and finish the bottom sheeting. Nothing to it. This is a pretty easy building project.