The In-Pond Skimmer acts as a pre-filter for the Tetra Pond Water Garden Pump(s). They are easy to install with flexible or pre-formed ponds. Keeps the pond clean by skimming off the debris before it sinks. 2 year limited warranty. The ideal, no-cut, pond skimmer for smaller ponds. TetraPond's In-pond Pond Skimmer may be just set in your pond: no liner cutting necessary. Handy design acts as a prefilter and helps keep the pond clear and free of surface debris. Compatible with TetraPond water garden pumps and waterfall filter.