This copper counterflow chiller is probably one of the fastest ways to chill wort.
This unit is similar in efficiency to the Chillout plate chiller, with the added benefit that it is easier to clean.
Whereas a plate chiller has small crevasses to trap hop material, the counterflow chiller can be more effectively flushed out after use.
These units are 9" in diameter and about 7" high.
The input and output are approximately 3/8" outside diameter (9.5 mm).
These can be used with gravity, although a pump is recommended.