Mag couplers

[hfx123]

So I'm looking for lar 15 coupler. I see some that give a curved/bent look then I saw others that make the two mags a straight stick. Is the the same coupler used differently or two different? I think they are both magwedge. I'd prefer straight look so I want to make sure before I buy

 

[mebiuspower]

2 different versions.