GE Profile 28 Owner's Manual page 36

Installing the water line.
Read these instructions completely and carefully.
Connect the Tubing to the Refrigerator
Before making the connection to the refrigerator, be sure the
refrigerator power cord is not plugged into the wall outlet.
We recommend installing a water filter if your water supply has sand or particles
that could clog the screen of the refrigerator's water valve. Install it in the water
line near the refrigerator.
1 Remove the plastic flexible cap from the water valve.
2 Place the compression nut and ferrule (sleeve) onto the end of the tubing as
shown.
3 Insert the end of the copper tubing into the water valve connection as far as
possible. While holding the tubing, tighten the fitting.
4 Fasten the copper tubing into the clamp provided to hold it in position.
You may need to pry open the clamp.
One of the illustrations below will look like the connection on your refrigerator.
Refrigerator Connection
1/4 Compression Nut
Refrigerator Connection
36
Ferrule (sleeve)
Tubing Clamp
Ferrule (sleeve)
1/4 Compression Nut
Tubing Clamp
1/4 Copper Tubing
1/4 Copper Tubing