This OSRAM 28w 2pin 835 (standard white) 2D Lamp comes with a GR8 cap type fitting. This energy efficient compact fluorescent lamp has an average lamp life of 10,000 hours and has a Class A energy rating. 2D lamps are normally used in corridors and general bulkhead fitting applications normally found in supermarkets, hotels, schools, shops and public buildings. This 28w 2pin application is for switch start control gear only, and will not work with high frequency control gear. This 2D lamp is also known as a PL-Q, CFL square, Butterfly lamp and a Double D lamp.