Osram powerball hci tt 250 w942 ndl pb metal halide lamp with an e40 cap the lamp is a single ended discharge lamp with extremely high efficiency that provides a white crisp light due to powerball ceramic technology the lamp is mainly used in in street and outdoor lighting in suitable luminaires indutrial installations exhibition halls and trade fairs it has a very long life of up to 24 000 hours and is dimmable if used with conventional control gears and electronic control