The Warrior is adjustable and comes with 3 sets of cam modules. Draw length goes from about 22-25", and weight is about from 20-30#, but because these are not the greatest bow in the world and the quality control isn't as good as it is with a "real" bow, the weights do vary - I've seen one as high as 35#. You also will need to correct the cam timing, as these are almost always out of tune.
HOWEVER...If your son is serious, he will outgrow this bow quickly, quality-wise, if not in draw length and weight.
I'd strongly suggest you spend the extra money and get a good quality youth bow, like a Diamond Edge or a Parker Sidekick. These will be much more accurate and more fun for him to shoot. They have draw length adjustments that will take him well into his teens, and can be upgraded into hunting weights. They also have much better resale value so you can get most of your money back if he quits or outgrows them.
