High-wattage double-envelope halogen lamps consisting of a quartz burner with a linear tungsten filamentcontained in a single-ended thermal shock-resistant tubular clear glass outer envelope.Theselamps are mainly used in floodlighting installations. In addition to their high luminous efficacy like all halogen lamps they produce crisp white light and offer dimming possibilities and immediate reignition.They should be used in enclosed luminaires or lighting systems. IDE double envelope lamps have a universal burning position