I made this because at times I might forget to bring a quarter when shopping. And other methods like inserting a fake quarter doesn't work since they swap out the carts at the casher at my Aldi.
This product, all you need to do is put a quarter in it and connect it to your keychain. When you need a buggy, take the quarter from the holder and use it like you normally would. Then when you bring back the cart, take the quarter from that and put it in the holder. This making it where it doesn't matter if the cashier swaps out your cart.
Note I used PLA to make mine. But that's only because I have more colors in that and this is a super easy print. I recommend aiming more towards PETG since PLA might warp due to heat.
As seen it is super easy to use.