Hello @Anonymous
Thank you for your post!
I did some research for you and unfortunately I was not able to find any in our content that reflects that sliding or varying length connectors mentioned in your post.
The item could be built using the standard CID, connectors as well, but connecting them together with a sliding length is going to be complex and may not be worth the headache.
I do think that this is a good idea for our Fabrication Ideas page, if you post there and send me the link I can vote up your idea.
Fabrication Ideas
Otherwise you may want to contact a re-seller and see if they are willing to build such content for you or they may already have it.
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If you found my post addressed your problem, please click on "Accept Solution" to help others with similar questions.
Thank you and I look forward to your thoughts!