The brand new range of air pumps from Hozelock come with everything you need to supply small & medium ponds with air. They are weatherproof & can be left outside uncovered making them very easy to install by your pond. Model Max Depth Tube Air Stones Non Return Valves 320lph 1.2m 10m 2 Small 2 640lph 1.2m 10m 4 Small 4 1500lph 2.0m 20m 2 Medium 2