Features: 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 Features 5 Adjustable LED Lights: This new version of the smart light balls Features 5 adjustable LED lights in red, blue, green, and multi-color options, providing a captivating and joyful experience for your pet. Convenient Remote Control: Equipped with a small wireless remote control with a range of 4 to 16.4 feet, offering ease and comfort during pet training and playtime. 3 Interactive Reaction Modes: The automatic balls offer 3 interactive reaction modes - roller, bounce, and automatic sleep, ensuring smooth and active interaction with pets. Durable and Safe Material: Made of high-impact ABS plastic and TPE outer shell, these pet balls are wear-resistant, drop-resistant, and safe for pets to play and chew. Stimulate Hunting Instinct: This electronic pet toy stimulates the hunting instinct, keeping pets mentally and physically active, making it the perfect toy for dogs and cats.