I haven't been able to search for this as I can't even think about how to explain what I want in a short phrase.

Problem
My handlebars are short on space due to interrupter levers and them being quite compact bars.

Possible Solution
A second bar running underneath the handlebars in front of the downtube, lights could then be attached to this.

Second Problem.
To do this I'd need some sort of clamp that would wrap around a round bar and allow another bar to be attached at 90degrees to the first bar.


Two of these attached to the handlebars would then support a secondary accessory bar.


What are these clamps called? Where can I get them? Is there an existing solution I could buy?