The MSR Guardian is one of the best waterfilters on the market. I really love it, but there is one drawback with it. It is not possible to filter with common PET-bottles. Why is this an issue? When you are on travel with some friends or you just want to fill up your water supplies it is quite unconvinient to share the filtered water with them, espacially if you have to filter >5liters. The adapter was created to be a suitable gadget which solves that problem. Therefore it provides a funnel to the inside of the bottle, this prevents loss of valuable water on the edge of the tread. The apperance corresponds to the original design while the additional caps are closeing the adapter on both ends in order to protect it. Now you are able to expand its usecase by filtering bottle by bottle without annoying capacity limits.

I´ve printed this on a FDM Printer with standard PLA: (supports activated; 0.4 nozzle; 0.2 Linehight; 3 Walls; 15% Infill, concentric).If you have any questiones don´t hesistate to message me.