Feature: 1. Selected high‑quality filter cotton + activated carbon materials, safe and durable to use. 2. Captures residues, fish residues, absorption of heavy metals, odors and decolorization, etc. 3. To get the best results, please replace the filter element as needed every 2 to 4 weeks. 4. Simply rinse with cold water to remove toner and insert it into filter slot, which can be replaced in a few seconds. 5. Fish tank filter cotton replacement, easy to install and remove, providing clean water for fish tank. Specification: Item Type: Filter Cotton Material: Filter Cotton + Activated Carbon Weight: Approx. 101g / 3.6oz Product Size: Approx. 135x55mm / 5.3x2.2in Package List: 6 x Filter Cotton Note: 1. Please allow 0‑1 inch error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.