After washing my water bottles (or canteen or travel mug or whatever you want to call it), there's always some residual water left in the bottom. If I leave it upright or sideways, it pools in the bottom and takes forever to dry. If I turn them upside down the water is trapped underneath and never dries.
This stand lifts the bottle up enough to give an air gap and tries to direct the draining water away and out of the bottle.
Measure the inside and outside diameter of the mouth of your bottle or use the included presets. If you have a different size bottle and measure the dimensions, post them in the comments and I'll add a preset for others to use.
Set the drip wall thickness to something appropriate for your printer. When you slice, either preview and make sure the drip cone prints, or set surface mode to "both" or "allow single extrusion walls" or whatever your slicer calls that setting.
The drip cone has a spherical hat. This both reduces height and removes the sharp and difficult to print point from the top. For small diameters, a driphat of 5mm works well. For larger diameters, you may want to use a larger hat size to reduce cone height; you can set the driphat to a value between 0 and 1 to make the hat a fraction (say 0.5) of the diameter instead.
Before printing, check the preview in your slicer to make sure the drip cone actually prints. If not, either increase the dripwall thickness or change your slicer settings to print thin walls anyway.
For very thin walls and large driphats, sometimes the spherical portion doesn't adhere well to the conical portion, so watch for that during printing.
An apparent bug in Cura causes gaps in the tops of thin spheres. This part may work despite this flaw.