(Blue) - The Katadyn Quick Fill Hydration Adapter connects your water filter to your hydration pack. Sized for virtually all hoses, the Quick Fill Hydration Adapter fits hydration packs with ¼" I.D. drink tubes (like Camelbak®, etc.). You can easily fill your hydration pack by connecting to the external drink hose or connecting to the quick-release fitting on the bladder. Two blue pieces are for the hydration pack tube (in order to easily remove the bite valve when connecting to filter) and one white for the water filter tube. The Katadyn Quick Fill Hydration Adapter lets you fill your hydration pack with clean, filtered water. Available at TravelCountry.com.