The wavelength selected for the LEDs of the chamber is 405 nm, because that is the wavelength required to cure most 3D printing UV resins, which in turn is the same as that of most UV curing adhesives. These wavelengths correspond to the UVA range, which represents the most "benign" range for human health.
If a different wavelength is required, it is enough to replace the LED's with a set of the correct wavelength, making this project very versatile. A correct matching of the required wavelength of the glue or resin will improve cure times dramatically.
If available, using shorter wavelengths (in the UVC domain) can provide an additional use of the chamber as a sterilization chamber.