I am selling a 45 ft counterflow chiller. Not sure of exact length since I bought it from the person who made it, but 12" diameter, so [12" x 3.14 x 14 loops] / 12" = ~45 ft estimated. Won't fit on my single tier rig, so I bought a plate chiller.
3/8" copper tubing with brass compression fittings. Has 1/2" female NPT fittings for wort in/out and garden hose fittings for water in/out. The outer house is regular garden hose, but I've never had any issues with hot water.
Very efficient CFC, but I'm not sure you'd get a good flow rate with a gravity feed since this is so long. It worked well for me with a March pump. Always recirculated PBW and rinsed with water after use.
Asking $80 shipped.