These clips are ment for the Ortlieb panniers with the QL1 / QL2 klick system.
https://www.ortlieb.com/de_en/ql1-ql2-hook-inserts
The originale ones come in the sizes 8mm and 11mm to fit the Bike rack.
These here are designed for Bike Rack tube diameter 8; 9; 10; 11; 12; 13mm, with 0,5mm play.
The author marked this model as their own original creation.