Twin 18650 Holder for Streamlight (taller)

This is a quick and dirty change to Macmade's Twin 18650 Holder.  This adds 3mm of height to accommodate Streamlight SL-B26 18650s and potentially other brands that include a battery management circuit on board.  You can download the screw on caps from the original model.

Print 0.2mm, your default settings are probably fine.  It is pretty strong, even with very little infill.  (Did a test print for sizing with 1 vertical wall and 10% infill and couldn't break it by hand).