The 591-3001-013F, from Dialight, is a CBI® circuit board indicator from their Prism® family. It consists of a 3mm surface mount (SMD) LED within a black plastic housing. The LED has a round, dome-shaped lens and is available in a range of bi-Color and tri-Color options. The 591-3001-013F indicator's black housing provides a high contrast ratio between itself and the LED light. The LED is positioned at a right angle, making it ideal for PDB indicator applications.