The original tool holder fits the Cricut Maker tool space perfectly, but a couple of my tools (rotary cutter and knife with their protective covers needed a larger space to fit into. I re-created the shape from the original tool insert model. The largest hole at the back fits two tools with their protective covers. The other two openings fit the narrower tools. The front and rear openings are tilted a few degrees to allow extra space between the three openings to accommodate the larger diameter of the quick swap gears.