LED Spa Light with 27 Ultra Bright LEDs, 12 volt use only. This very bright LED is a cluster of 27 LED, red, blue, green, and white, with 22 different color patterns selectable by cycling the power source on-off, creating a new color with each cycling. Suitable for use with air switched or electronic spa controls. White LEDs allow colors such as pink, light blue, light purple, colors which are not available with other types of LEDs. Will work with front access light niches, allowing use in whirlpool bath tubs too. Diameter is approximately 1-3/4" (44.5mm).