1УБЕ-40/220-ВП-05У4 (Луйс)

Retrieved from an unidentified fixture. It worked there in tandem with 1UBI choke. I have no clue on what is the difference with the 051 series. The quality is disgusting. Ignites the lamp from the 3-4 attempt and hums like a tractor. Together with its "partner" they were set aside and replaced with electronic ballasts.