Most gyms don't have 1.25lb plates. These are very useful for upper body progression workouts.
If you print two of the halves, you can fill the inside with weight and glue them together. I used pennies (~186 per half) to get to 1.25lb. You could also use concrete, or maybe sand. The middle piece isn't required, but if you want further strength, you can glue that onto the middle.
Fits a standard barbell (2inch diameter). There is no rattling or any sounds from the coins.
NOTE: There is another design for 1.25lb plates but I found it too large and unnecessarily complicated. This is not a remix.
I used tape to stack the pennies in groups of 12, then hotglued any extra pennies to reach 1.25lb. One of my halves actually failed right before the top solid layers, and it still works fine.