I think both- Input/output uses 13mm hose.I believe the tubing is 12/16mm for the Eheim 2215.
You might be able to find it at the hardware store.
Thanks for telling the perfect size for 2215. Got it from the lowes. Just $4.55 for 10'Get the 5/8 "(16mm) outter 1/2 (12mm)" inner diameter vinyl tubing , that's what I use and the right size for the 2215. They sell it precut in 10' rolls, its about $5.