Lid or Hood Tanks are sold with a lid different from the light, or the lid and light-weight could be joined into a single device called the "hood." The lid part addresses the tank and serves to prevent fish from leaping out from the tank. For goods you buy often, https://aquariumrepairservices.fashion.blog/2024/02/19/4-things-new-aquarists-keeping-flowerhorn-fish-should-maintain/