Baby Outdoor Gear

What is the key bit of material on a clip that is slid into a tube and snaps and 2 tubes called?
I saw on tubes aluminum for bike trailers, outdoor baby jumpers, folding shovels, … the two tubes are mounted so it slides over the other and this piece of hardware, and locks them. The button clicks then through a hole on the biggest hit when the two are connected peices.
Miscellaneous names: "Spring Pins," "Push," "Ball Nose" depends on where and how they are used. Most of them are used lightly hold something in position as a cabinet door. But I think that's what you need …. McMaster Carr catalog calls them by technical name "Quick-Release Connectors for Button telescoping tubes" part number 92988A730
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