About it's only limitation is that it is smaller than most home made ones but the major positive is that it is a self contained, recirculating unit needing only about 5 to 8 gallons of water. No other recircs anywhere that I have seen. There are only one or maybe two other units sold commercially. The one that I know of for sure utilizes a manual bilge pump so one can pump from a creek or a pond while at the same time rocking the box. Neat concept. Stream sluices are the much preferred units but they require running water with sufficient flow, drop and depth. Not always available especially here in the desert.