These are not the cheap/dim strobes you will find from most suppliers.  Professional grade strobing LEDs used by Police and civil services across the nation.  These are extremely bright strobing LEDs and should be used with discretion. Dimensions: 0.85"H x 4.5"L x 0.85"W, 9-13 Volt DC Syncable, 19 flash patterns. Available in White, Red, Blue, Amber, Green, Red/White, Blue/White, Amber/White, and Green  FREE SHIPPING