The red plastic coupler that connects the lens housing with the flashlight body tends to break easily, so here's the replacement you need.
This is a replacement coupler for the Nebo Redline OC/Redline Classic OC LED Flashlight
(Models: 6273, 6092 and possibly others, the red band is about 1mm wide - See Photo)
** This has only been tested on the NEBO OC, it may fit other models such as the NEBO Blast but they haven't been tested.
NOTE: This version
does not fit the NEBO Redline Flashlights with the
wider 4mm band (Models 5599, 5557, 5610, etc..)
You can find a coupler for those models here:
https://www.shapeways.com/product/UD7PUW7JF/nebo-redline-led-flashlight-bumpy-v2
This version has a bumpy indented pattern around the redline band. Looks cool with the light on or off.
Note: The strong and flexible plastics have a variation of ± 0.15mm, then ± 0.15%. Since the threads have fine tolerances, sometimes parts are printed too small so that the threads won't engage. Please report these to Shapeways support and have them print you another, also please send me feedback, so I can make adjustments if needed.
Sorry, Turns out this version isn't printable using the Acrylic Plastics (thin walls).
Prints well using any of the Strong & Flexible Plastics.