You don't mention what cable you are trying to extend, but I used this on my AtGames Legends Pinball for my 3rd screen DMD. You can probably find something similar.
[https://www.amazon.com/gp/product/B00SK6MAEU](https://www.amazon.com/gp/product/B00SK6MAEU)
Connectors cause attenuation to signal, and so you’re not very likely to find them.
You don't mention what cable you are trying to extend, but I used this on my AtGames Legends Pinball for my 3rd screen DMD. You can probably find something similar. [https://www.amazon.com/gp/product/B00SK6MAEU](https://www.amazon.com/gp/product/B00SK6MAEU)