Hello, the potty is rather small for tall 4 year olds. We also bought the product when our son was 4 years old (also tall and afraid of the toilet). He disassembled the potty several times but otherwise didn't use it much ;-)

The potty is not much higher than a normal one, but because the seat is straight, the little ones don't have to squat down too much. For us, it fit well until the age of 4. After that it was no longer needed.