Now includes our exclusive patented color anodized extended focusing ring in your choice of blue, red, violet, black, green or clear anodizing. These single-element AR coated glass lens assemblies are significantly more efficient at light transmission than traditional 3-element lenses, and can boost the output of your 405nm & 445nm device by 10-30% or more! Best for when you want the absolute maximum power and brightness for burning and close-up work. Note: The G-2 lens provides somewhat higher beam divergence due to the single-element design, and the 'spot' will not be as 'clean' as with the standard 3-element lens. In addition, this lens may be a very tight fit with the SL-LS1 external lens spring because the lens must be threaded nearly all the way into the diode module for proper focus. Trimming the spring slightly with wire cutters will alleviate this problem.