The Rhino Hobby Filter is a professional-grade filter designed for the hobby grower. Like the Rhino-Pro filter they contain Australian-mined RC412 carbon, which is the purest activated carbon available. The product has been designed with a fully reversible neck to give maximum flexibility. The Rhino Hobby Filter has a 30mm carbon bed and this lighter more compact filter. Same performance as the rhino pro the difference being the rhino-hobby as a life span of 9 to 12 months where as the rhino pro as a 18 months to 2 year life span.