Review on Anderson Metals Fitting Reducing Nipple by Mario Schultz

page 3/8 does not fit. Under the bathroom sink, the water supply line had this weird one-piece supply line that connects to 1/2", but the faucet needs a 3/8 Comp (aka 9/16-24 UNEF) to connect to the water line You may think you need a 3/8" to 1/2" male brass converter, but apparently there are different types of 3/8. It doesn't work - the 1/2" side was ok, but the 3/8" side was completely wrong. Search Amazon for 3/8" OD x 1/2 NPT if you are looking for that under sink part. .