Adjustment is not possible

Our children play hockey and do not require the mouthguard. The mouthguard of Adidas convinced me initially through the Amazon reviews and the price. All thing turned out after delivery that an adjustment of the mouthguard (as explained in the enclosed product description) in the teeth of our guys was hardly possible. We will therefore revert to the product from another manufacturer, which has already proven itself in our guys, but more than twice as expensive as the mouthguard Junior Adidas.