"These are NOT 25cm x 25cm - they are in fact 25.5cm x 25.5cm, something I only thought to check after the 50cm x 50cm frame I bought to put my four in arrived. So now I have the choice of taking a hacksaw to them or accepting that I've wasted money on both the frame and the baseplates.
They're absolutely fine for what they're made for - they take the bricks and they provide a good base for builds, but they are not as described on the website."