I have seen mention of these.
They seem to be a way of adapting 2-line deltas so that they can be flown with 4 lines.
Not sure I can see the logic of this. I'd have thought that deltas fly pretty well with two lines.
Unless the idea is to give wannabe Rev owners a chance to try flying with 4 lines without actually buying a quad line kite?
Except that the delta flyer then has to equip himself (herself) with a set of 4 decent matching lines. Not cheap. Plus the handles. And the q-flaps themselves don't seem to be cheap either - I couldn't find any on sale in the UK, but in USA they seem to cost nigh on $30.
Are they a good idea? Can they be said to enhance the delta kite experience? Are they a sensible (intermediate) option for dual-line pilots looking to cross over to the dark side?