This Counterflow copper wort chiller is a very good conductor of heat.

They are similarly as efficient as the 30 plate chillers however they are easier to clean as they do not have all the small crevasses to trap hop material and other solids.

These units are 23cm in diameter and about 18cm high. The input and output are approximately 10mm outside diameter. The hot wort flow can be used with gravity but are recommended to use with a pump.

For the cold water flow, using mains pressure, do not restrict the outflow in any way or you could burst the outer polymere layer.

Warranty does not cover bursts/ruptures/blowouts of this outer layer resultant from having a kink in your output hose, restricting attachments on the output (such as sprinklers) or similar. Always ensure the output hose is free from any pressure buildup when using unregulated mains water. 

For efficient cooling Always ensure your hose attachments and flow of liquids is 'counter flow'..that is in opposite directions.