I haven't seen any other builds using LED fittings so I'll be happy to claim this is a first, but not without expressing just how much a pain in the **** these fittings are to build with.
The LED's are on a circular PCB which sits over male barb with two o rings:
The fittings come in a box with the o rings fitted, the cable with the LED is loose in the box so it means having to fit it yourself.
To begin you need to remove the o rings, then very very (VERY) gently slide the LED pcb ring over the barb. With it being such a tight fit and the surface LEDs being so close to the edge of the pcb, even if you're incredibly careful it is easy to knock one off. If you do knock a LED off, the other LED's will stay lit, but the effect over a length of tubing is dulled and looks out of place compared to the rest.
With the LEDs being so tiny, I find it hard to believe the manufacturer can accurately place and solder each LED identically on the pcb. Any inconsistency pretty much guarantees you're going to lose a LED during fitting. I was really really careful and I Ended up with 5 rings missing a LED and another with a damaged trace which causes it to flicker when lit.
Then comes the fun with the tubing
No other hardline fittings use an internal diameter barb. At least I can't think of any..
When the tubing is manufactured, I would assume the manufacturer prioritises accuracy of the outer diameter over the accuracy of the inner diameter. Thinking about it, internal diameter is relatively unimportant to most fittings, I doubt it is much of a concern.
Out of 4 large boxes of the Alphacool 13/16mm PETG tubing I found only one batch of the tubing to be a perfect match to the barb I say perfect match because if it isn't and it's out by as little as 10th of a mm... the fittings will leak like crazy (you can imagine how much time it took rebending each piece and leak testing before I realised some batches of tubing will never work)
For these reasons, and many more, I would thoroughly not recommend buying these fittings and trying this yourself. If you value your hair and sanity I wouldn't even think about it lol.
Saying this, the results well.. I'm very pleased