Philips Lighting 21840 21W Master TL5 high-efficiency fluorescent lamp with a tubular 16mm envelope and G5 base. Cool white in colour. Highly efficient 3-band fluorescent coating in combination with precoating. It is specifically designed for operation with electronic gear and well suited for dimming. It is ideally suited for recessed, surface-mounted and suspended luminaires in applications like offices, shops, schools, public buildings and industry, wherever high-quality, energy-effective lighting is required.