Tungsten halogen G4 capsule light bulbs produce a 1A colour rendering index are often used in display and accent light fixtures, providing an extremely compact light source.Constructed from UV stop glass, thus removing the need for additional UV protection. This dimmable 10W G4 (M91) capsule produces 130 initial lumens in a 2850K warm white colour and has a nominal life span of 2,000 hours.1A colour rendering index. Dimmable. UV top glass. Fitted with a G4 2-pin (4mm apart) base.