A racket may include a frame including at least one prepreg layer. The light sensor is connected to a platform andor to a film for detecting an intensity of a light within the interior of the compartment. The hydroxyl content of the prepared composition depends on the amount of the multi-functional hydroxyl compound used in the preparation. The flange provides a ramped edge tapered substantially uniformly over a distance of between 10 and 20 times the maximum thickness of the flange.