Redsea Y-Split nozzle issue

[Bent17]

Just bought myself a Redsea Y-split for my return nozzle on my Redea 425. I can't figure out how to install it. The diamater of the y-split and the return nozzle are the same and I tried pulling out the return nozzle but nothing seems to move. Any help?

 

[Bent17]

anyone having the same issue as me?

 

[Bent17]

anyone??