[High-Efficiency Filtration] This water filter element set replaces Gravity Filtration System filters and has passed rigorous testing by authoritative institutions. It effectively reduces chlorine, fluoride, heavy metals, taste, odor, sediment, particles, and other harmful substances. Enjoy clean and healthy water outdoors anytime. [For Black Filter] The black filter is made of high-quality materials and boasts a higher adsorption capacity than ordinary granular activated carbon. It effectively reduces fluoride and chlorine, filtering out impurities. [For Fluoride Filter] This fluoride and reduction element replacement filter adsorbs fluoride, (V), pre-oxidized (III), and other residual typical heavy metal ions. [Perfectly Compatible] This filter element set is compatible with Gravity Filtration System filters, including FOR Super Sterasyl and Traveler, Royal, Big, Imperial, and Crown Series. For optimal performance, we recommend replacing the water filter every 1000 gallons and the black filter every 6000 gallons, or based on your water conditions. Material: plastic Color: white+black Package Contents: 2 x for water filter 2 x for water filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.