Gaggion has removed the moulding sprue from the alignment edge of its LLC25x colour-mixing collimator range, so they will now sit flush on a flat mounting annulus, with no need for a notch. These are 32mm optics, with non-chip-imaging characteristics to create even beams from single or multi-chips RGBW, tunable white or standard white leds. See ...
This story continues at Gaggione simplifies fitting of LLC25x collimators
Or just read more coverage at Electronics Weekly