Eheim Hose Size?

[Tiger Tiger]

I buy a 2217 external eheim filter and thought it was a good idea to order a coupling. on the tube size it said 16 mm, so i order a 16mm online. The coupling arrives and i get to work. But the screw fastner will not tighten up on the hose.
I look again and it says 16/22 , then i look at the piping i already have in place it says 12/16?

So what do these two figures mean?

Is it 'It will fit a 12-16 mm and a 16-22 mm in which case it should fit.
Should i have said 16/22?
I just assumed a 16mm hose.

What's the theory and i guess if it is wrong what i ordered it is confusing and is there a way round this.

 

[BigC]

LOL
Yeah sometimes it is confusing the way Eheim lay out their hose and fitting sizes
For your filter (I've got one) you need 16/22 for the intake side and 12/16 for the return that applies to pipe and accesories such as taps and bends etc.
Regards
BigC

 

[adamgreen240]

The two measurements are internal and internal So 16/22mm hosing has a 16mm internal dimension and 22 external.

You need the 12/16