About this 3D model

This is a dropper bottle topper with a recessed area to paint the color that's inside the bottle. You don't have to glue these on, with just pushing them on with a twist they stick on the tops so well I've never had any fall off without a good amount of effort to remove them. I've only used them on Army Painter and Vallejo bottles but I'd assume they'll work on pretty much any 17ml dropper bottle top.