When I first setup my tank(got all the stuff used) I had the same problem with the 3/4" nozzles(actually broke one). Turns out they fit genuine loc line perfectly but the used stuff that came with my tank was made with thicker material so the nozzles weren't big enough to snap over the end.Printed a few of these in 1/4" for my evo with no massively noticeable impacts. I could not get the ABS material ones to snap on no matter what I tried.