The Nitecore TSL10i is a replacement tail cap that fits the Nitecore i Generation series of lights, which currently includes the i4000R, P20i and P10i.
Four coloured lights of White, Red, Blue and Green are built into the tail cap with multiple flashing modes.
Three separate switches allow for the ultimate user interface with separate power, mode and signal light buttons. The signal light has mode memory that automatically remembers the last used setting. The mode button allows for instant access to strobe from off and the power button has momentary-on functionality.