That’s a good question – durability is critical given it is repeatedly being hit! Its appearance suggests it might not be as robust as other training aids. But it is deceptively strong – not one TopspinPro has been returned because it was broken by someone hitting it.
Having said that, It’s not designed for a full-blooded flat forehand drive but rather for teaching the correct bio-mechanics for topspin groundstrokes. If you hit it correctly it will barely move (I can hit it as hard as I can and it won’t move). But if you swing horizontally you’ll knock it over. But that is in fact the point. The only way to get the ball to spin WITHOUT hitting the screens is the correct way of hitting groundstrokes. And it intentionally requires some concentration to do that. If one wants something just to whack, then the EyeCoach is better. But it won’t teach you topspin 🙂
Even if it is hit incorrectly and knocked over it will never break. One just has to pick it up again.