The X9 is available with three battery options, 10.4Ah, 15.6Ah and 20.8Ah. Once you've decided on the battery, pick the colour; orange, white or grey.
The X9 standard edition is available with the 10.4Ah battery option. Ideal if you're looking for a 500W scooter for a small commute where range isn't the main factor. The advantage of the smaller battery is the scooter is cheaper as well as lighter. If you're not going to need the additional range of the Plus or Max editions then don't spend more than you need to.
The 15.6Ah battery is available in the X9 Plus. With a "real world" range of around 20miles (38miles range in test conditions). Aimed at those who are looking for an extension in the scooter's range or for those who don't want to charge the scooter every day.
The X9 Max comes equipped with the 20.8Ah battery, with a tested range of 56 miles you'll be looking at a "real world" range of around 25 miles. But with the larger ranges comes with the largest price tag and also it's the heaviest of the three scooters.
All scooters come with the same 500W motor driving the rear wheel for a stable ride.