Help with needed metric union/fitting

[Spinner]

I bought a H&S skimmer with no pumps or the other part of skimmer pump connection fittings for both the inlets and outlets.
Attached to the skimmer is only part of needed unions. Now the tricky part what size metric are they....20mm & 25mm?
Hope the pictures help:)

They are to different sizes with bottom ones inlets being larger than top ones outlets.
Thanks for the help!!!

 

[Reefing Madness]

Aquarium Specialty - Aquarium Supplies & Marine Aquarium Supplies
E-mail them, they can give you the info to get the parts needed to fit those.