Hi Troy Boy,
Responding to your PM and public post at the same time. I hope you don't mind.
Yes, you need a Woods Glass filter or similar UV-pass filter. I've seen some dichroic filters that claim to have a fairly narrow 365nm bandpass, although I haven't tried one yet. They're actually silver in appearance. B&H Photo sells them in the States. They're probably more expensive than the one you saw on Alibaba though.
It bugs me a little that a 365nm LED produces multiple wavelengths, some of them visible. The whole idea is to produce an invisible light source. Some UV LEDs are even built in a plastic substrate that fluoresces white! I don't know what they were thinking there.
I'll look around form some possible filters for the CroLED and I'll let you know if I find anything good.
pw
quality 365nm UV LEDs like SST-10 UV and Nichia for example do not emit visible wastelight
just a faint purple glow as your Eye can see down to almost 380nm
ZWB2 filter is available in 21mm for common flashlight sizes