The PAL Multi-Color Evenglow Spa Light is made from high performance engineering plastic with thermoplastic for heat transfer and 40% glass for greater strength. Providing more resistance to thermal shock than glass. With an over molded design for dry connection the detachable design is made for plug and play. It's a simple disconnection for servicing or winterizing. Choose the light with excellent resistance to most swimming pool chemicals and the finest optical grade (more transparence than glass), and UV stable properties for light efficiency.