Hijibahi

How would I go about using them between 2 tubes? say I want an angle but not at a waterblock/radiator, how would I go about using that?

Can someone explain to me how these angle fittings work because only 1 side to me looks like it actually works, how do I install the female thread side to my system? Do I need a regular compression fitting and use the male thread on that with the female thread on the angle fitting meaning I need to have 2 fittings? https://www.overclockers.co.uk/ek-water-blocks-ek-af-angled-90-degrees-g1-4-inch-nickel-wc-688-ek.html