Freestyle scooter wheels come in different diameters and widths. Beginners should usually stick to 100mm or 110mm wheels. Intermediate to pro riders can go for the 120mm and 125mm range. The Standard wheel width for scooters is 24mm but 30mm wheels are taking over. Pro scooter wheels also come in 26mm and 28mm. Wheel cores can be spoked, have a solid metal core, or a hollow core. Hollow cores and honey core wheels are the most popular due to their light weight. Keep in mind metal core and and spoked core wheels weigh only ounces more than hollow cores so pick the wheels that you think look the best on your trick scooter.
In conclusion, consider scooter wheel brake compatibility on your scooter deck and wheel compatibility of your forks. If you are purchasing 120mm scooter wheels, your forks and deck brake must also be able to fit 120mm wheels.