Well got one BP-MBWP-C33 delivered, is a 11mm barb. Post I started is slightly wrong , should be 7/16 barb. The Tygon R 6012 norprene is not hard to push over the barb, because the hose can stretch more as a PVC hose, getting of is harder, need to cut the hose for getting the hose of the barb. I want to use the norprene hose, is a 3/8id-5/8od hose, so 9,6mm ID to 15,9mm OD hose. With the BP 11mm barb I can use my phobya aluminium clamps, I only need to open them a little more, and when screwed in, the clamps have 16mm ID inside, so the hose get a little more as 1 mm fixing pressure around it on the barb, if I am right. Now I read some where here on the forum , that one member did used this same hose with a compression fitting and it was a 11ID/16OD fitting. I like the look of the norprene, did looked for the LRT, but to shiny for me, everything in the Case has a matt black finish, so the norprene hose will blend in nicely. So putting a 3/8id hose on a 7/16 barb should be the same as putting a 7/16 hose on a 1/2 barb. Correct me if I am wrong. Greetz