These acrylic balls offer high light transmittance with a Refractive Index of 1.49 and can be easily heat-formed without loss of optical clarity. Prolonged exposure to moisture, or even total immersion in water, does not significantly effect the mechanical or optical properties of our acrylic balls. These acrylic balls have been UV stabilized for good weather ability and resistance prolonged sunlight exposure. Acrylic balls are unaffected by aqueous solutions of most laboratory chemicals, by detergents, cleaners, dilute inorganic acids, alkalis, and aliphatic hydrocarbons — however, acrylics are NOT recommended for use with chlorinated or aromatic hydrocarbons, esters, or ketones.