Wanted more practice 3d modeling and my climbing gear seemed like a great challenge. The carabiner can be printed in one piece and although not spring assisted the gate opens and closes.

Printing:

I have an unmodified stock creality Ender 3. (with a glass bed)

Nozzle: 0.4mm.
Filament: 1.75mm PLA
Max. Print Speed: 200mm/s.
Max. Layer Resolution: 0.1mm.
Print Precision: +/-0.1mm.
Heated Bed: Yes.