[Tired Old Man]

You can use a pair of the Rocket City/Nelson Hobby links and join them together with a vey short piece of 4-40 all thread. You can get the ends of the ball linkls to touch that way if you want. The shortest Pro Links leave a bit of a spread between them but are a lot easier to adjust.

The downside of the pro links is that you have to buy some ball links that are either not threaded (Dubro or special Rocket City) or have left hand threads for one end of the Pro Link. I believe you can get them from Nelson Hobby and H-9. The Nelson/Rocket City parts are much better than the H-9.

Wild Hare R/C also carries a similar ball link. It's the closest to the Rocket City design of any others on the market that I'm aware of. I would call or e-mail him to see if he has any that come unthreaded.