Compatible models: The black purification elements match the original brand perfectly. Compatible with Berkeyy Travel, Big, Royal, Imperial, Crown Series, Propur Traveler, Nomad, King, Big Series, gravity filter system. Sterasyl and ATC Super Sterasyl filter, system W9361122 and W9361123. This washer and wing nut are precision engineered for a perfect fit to stop any leaks. Safe Materials: Our replacement filters are made from high quality natural coconut shell activated carbon. We strictly control the filter material and adopt lead-free and BPA-free materials to produce the filter housing, which ensures excellent removal performance that will not filter pollutants into the water. Easy to carry: Ideal for home, travel, outdoor activities and emergencies, such as water shortage, the filter can provide you with healthy, clean, high-quality water both at home and outdoors. Longer useful life: To extend the life of your unit and achieve optimal performance, we recommend replacing the filter every 6,000 gallons per pair, which varies depending on water conditions. Note: Data are all measured manually, please allow 1-3cm error due to differences in light and display, there may be color differences, please refer to the actual item received.