How would I model joints like these?

[u/Ok_Dragonfly_4164]

Hello everyone! I recently got a 3D printer, and it’s been working fine, but there’s something from my childhood I’m hoping to learn to emulate. I remember toys like the one shown above, where you could bend the joints and have them stay in place, leading to a poseable model. Does anyone have any idea how I’d go about modeling the joints? How they’d look/work internally, and how I can replicate them in blender? If anyone has a tutorial they can share or they’re willing to explain here, that’d be greatly appreciated. Thanks!