Most fresh water tanks are shipped without pre-installed fittings to allow customization for each RV. Returns of unused tanks are possible but subject to approval and may involve shipping costs. We offer a Universal Fittings Kit designed to fit most fresh water tanks, which you can install yourself or have professionally installed. For sensor installation, this kit also supports adding water level sensors compatible with your original sensors. Additionally, we provide a Custom Fittings Install Service with spinweld installation for up to five parts, priced at $208.33, although this service may not always be available. To proceed with fittings installation, you can mark your tank diagram with desired fitting locations and email it to our team for a quote and instructions. This approach helps avoid costly returns and ensures your tank matches your RV's specifications.