A Nichia UV LED with pass band of 365 nm is shown below in a prototype build with an A-19 head and 19 mm reflector.
The LED is a smd and I attached crude tin plated loop leads to the side of the LED for lead wire attachment points. The LED is driven at 520 mA of constant current by a Wiz2 converter. Below, the top and bottom of the LED is shown next to a Luxeon LuxIII LED for scale. Although not clear in the picture, there is a 4x4 grid of 16 squares on the die.
Below are two lights with the Nichia in the A-19 on the left and a Cree 7090 UV hosted in a custom light on the right.
There is some visible light from the Nichia but not enough to be certain that the light is on in any significant ambient light unless there are objects in the beam path which will fluoresce. Tritium vials are located inside the lip of the bezel to alert one to the fact that the light is turned on.
The "PD" below is a custom one off head and bezel made to host the Nichia 365 and a McR-19. The bezel has some milling to allow for 3 ea. H3 vials that seat in longitudinal slots recessed and the bezel is further relieved from the rear to allow for excitation from the UV LED and they serve as indicators that the UV LED is lit.
The Ti clip was anodized a violet/ blue color for personal identification of this particular light; not that the H3 vials aren't unique by themselves.