For your Dutchmen by Thor RV window opening of 55" wide by 26" long with a 1 1/8" deep headrail, we recommend custom RV day/night pleated shades specifically designed for tight spaces. Our custom pleated window day/night shades can be ordered in your exact dimensions, ensuring a perfect fit and smooth operation. You can select from multiple colors to match your RV interior. Ordering the actual length of 26 inches is advised, and adjustments will be made during production to accommodate your installation requirements. Visit our custom builder page at Elkhart RV Parts to configure your shade, and contact us anytime for assistance with your order or questions.