Features: 1. This is a breathing biological ring made by nanotechnology. 2. The biological ring is fired at high temperature. Durable and high quality. 3. Promote create abundant and diverse nature elements and essential minerals and microelement. 4. Effectively help restore the nature water quality and provide the most suitable living environment for your fish. 5. Great for using in fish tank, aquarium, effectively purify water. Notice: 1. Actual color may be slightly different from the image due to different monitor and light effect. Please allow 1-3cm deviation due to manual measurement. Specification: Product size: 12*12*10cm (single size: 1.9*1.7mm) Color: brown-red, light yellow, white Weight: about 250g List: about 250g filter media*1 Package List: 1 x filter media(about 250g)