Acrylosilane polymers containing vinyl silanes are prepared by copolymerizing vinyl alkoxy silane monomers predominantly with, or in the alternative, only with acrylate monomers. The assembled device is used as part of a golf club fitting system to emulate the swingweight of various production golf clubs. This \u201cleaky\u201d effect can be used in conjunction with a reflector sheet in a tapered-waveguide arrangement to construct a lightweight backlight. A focusing lens is located between the collimating lens and the optical waveguide.