The DTR-G-2 is a high pass short focal length single element 400nm-700nm AR broadband coated glass lens in an standard M9x0.5mm threaded barrel with focus ring. The threaded mount is precision machined out of pure brass to prevent thermal shifting of the optics and fine threads to keep centered and in a permanent fixed position when using teflon to lock in place for high tolerance applications like light show units or correction/combination modules like this.
Here are some examples of collimation with different diodes.
For CNC Engraving/Cutting these can make the smallest spot with the highest power density but requires a very short working distance of 30mm from the aperture to the work. Efficient ventilation is crucial with this setup.