diffusion surface on the cover or multiple collimating zone element diffuses the display aspect obscuring the individual leds a diameter of the optical features of the diffusion surface is smaller than a diameter of the optical segments the led symbol signal may be configured for retrofitting into an incandescent lamp signal housing application_number US 12257602 A description led signals are disclosed in detail in u s patent application ser no 09 756 670 filed jan 9 2001 and further in u s patent application ser no 09 827 429 filed apr 6 2001 both applications assigned to applicant gelcore llc and hereby incorporated by reference in their entirety one embodiment of the present invention is shown in fig1 a a printed circuit board pcb 5 includes power supply circuitry and leds 8 grouped in clusters of at least one led 8 each arranged in the form of a desired symbol here a directional arrow the pcb 5 is mounted in a housing 4 with integral power connection 10 as shown in fig7 the housing 4 may be dimensioned to permit retrofitting of the invention into existing incandescent light signal housings upon removal of the original incandescent light bulb and lens es power connection to existing signal housings may be via an incandescent socket power connector 17 use of the socket power connector 17 removes the need for electricians to be involved in signal retrofitting activities mounted in on the housing 4 spaced away from the pcb 5 is an optical element in the form of a multiple collimating zone element mcze 3 portions of the mcze 3 not desired as part of the symbol are covered by.