The FinyPetz Aquarium Double Isolation Box FH-20 is a practical and safe solution for fish breeding, isolation, acclimation, and recovery inside your aquarium. Designed with a dual-chamber layout and removable divider, this isolation box allows you to separate fish efficiently without disturbing the main tank environment. Ideal for breeding betta fish, guppies, fry, and small tropical fish, the FH-20 isolation box protects newborn fry from adult fish while ensuring proper water circulation through multiple ventilation holes. This helps maintain oxygen flow and stable water conditions without the need for extra pumps or equipment. Made from high-quality, transparent plastic, the isolation box allows clear visibility of fish activity while reducing stress. It is especially useful for injured, aggressive, or sick fish, providing a safe recovery space during treatment or observation. The box installs easily inside most aquariums using secure hooks, making it suitable for freshwater fish tanks, home aquariums, breeding tanks, and hobby setups. Whether you are a beginner or an experienced aquarist, this double isolation and breeding box is an essential aquarium accessory.