OK. I have to show my ignorance here. If I have an Airtronics receiver and Futaba servos, do I need to order Airtronics or Futaba servo extensions... or does it even matter? It's probably a stupid question, but I'm still learning.

Thanks!!

Depends on which Airtronics receiver you have. Is it blue? That might seem like a silly question, but Airtronics did smart thing when they switched from the old "Airtronics" connector to the newer "Z" connector. If the Airtronics item in question is blue, it's the new "Z" connector. If it is black, it's the old "Airtronics" connector.

Z is the same as JR and Hitec's universal connector. The wiring is the same as Futaba. Futaba puts an alignment tab on their male connectors. All you have to do with your Futaba servos is carefully trim the little alignment tab off with a razor blade or knife. If you don't want to cut the tab off at the servo end, order Futaba extensions and cut the tab off of the extension's male plug. If you want to use universal extensions, cut the tab off on the Futaba servo's male plug.

It's a blue one. So, from what I'm reading, it doesn't matter which one I order? I just have to cut the tab off to make whichever one fit?

Yes to both questions. My suggestion would be to buy the universal extension and cut the tab off of the servo. Where Futaba connectors are squared, universal connectors have cut corners on one side. Trying to plug a Futaba connector into a receiver that's full of other connections isn't as easy as using a universal. It's not hard, it's just not as easy.

Perfect. Thanks for the response!