Pondmaster PM1000 12" x 12" Filter Box. This low-profile filter is designed to be unobtrusive in the bottom of your pond. It has a locking handle for easy access and comes with carbon and polyester media for mechanical, biological, and chemical filtration. It connects to the intake side of the pump and is complete with 3/4" ID tubing and fittings. More than one filter can be connected to a pump for increased filtration capacity. Suitable for small to medium ponds.