This is a 38w Philips PL-Q (2D) Lamp with a 4 pin base (GR10q). This energy efficient compact fluorescent lamp has an average lamp life of 13,000 hours and comes in the colour cool white, 840 (kelvin rating 4100k). These dimmable lamps have a Class A energy rating and are compatible with electronic ballasts. 2D lamps are ideal for use in corridors, bathrooms or staircases and can regularly be found in supermarkets, hotels, schools, shops and public buildings. 2D lamps may also be known as PL-Q, CFL square, Butterfly lamps or Double D lamps.