Those look to be the Legris aka push-fit, aka plug'n'cool type fittings. I can also get them from AlphaCool in the correct size. I may be wrong, but I don't think you can use Tygon tubing with those fittings. You need to use the stiff PVC type. If someone knows different, please post...I think I will be OK with the straight compression fittings..Thanks.