Flat square screw neck refillable glass dropper bottles for essential oil packaging,the capacity will be 30ml 50ml and 100ml,out neck diamter is 18mm. most of the clients choose the transparent bottle and made with screen printing logo, or do the hot stamping silver / golden.
link:https://www.yongshineglass.com/dropper-glass-bottle/square-glass-bottle-dropper.html