My vet told me that my birds (parakeets like in the below image)

may have calcium absorption problems in the long term because their exposition to UV light is low (they do not receive direct sunlight, only through glasses in a balcony). I was looking for UV lights for birds in amazon and all I found was some black bulbs which need a socket (the classic bulb everyone has at home but in black instead of white) and that would require a somewhat cumbersome setup given my home and specifically the place where I intend to expose them to the light.

Then I looked for UV lights in general (not specifically for birds) and I came across with this specific item:

its description says that its wavelength is 395 nm whereas the description for those "specific for birds" bulbs do not specify wavelength/frequency. Both lights do specify they are also useful for checking counterfeit money, if it's of any help that they have this in common (similar wavelength maybe)

My question is: given that the linked item is convenient from a setup perspective, is it safe/good for my birds even if its description doesn't say so?

Bonus points for recomendation on how much time of exposition and best time of the day I should expose them to the light