How tall is this sliding door guide?

We recently remodeled a home and had to build a header when we replaced floor-to-ceiling bi-fold closet doors with sliding doors. We knew we were purchasing a high stack carpet (frieze), so we built the header a little higher up than the measurement so that the doors would slide easily. However, now our standard closet floor guide is too short to catch the doors! So, how tall is the 23-203 guide so that we can measure to determine if it will catch the doors or not.