When you’re with a group of friends and you all have identical looking beverages, what is to stop you from grabbing the wrong one and drinking out of it? Or worse, what’s to stop your friend from doing the same thing? It’s a problem that finally has a solution, says ABC7 Chicago.

Drinkmarx are customizable drink markers that attach to water bottles to tell them apart in a group. They are available in a variety of colors and designs; the markers are reusable and fit any drink container.

Inventor Christine Holland from Downers Grove came up with the idea for a better way to keep track of water bottles while at her son’s soccer game a year and a half ago. She says the colorful markers help end confusion at sport events or while working out at a health club; and they eliminate waste from paper cups and plastic bottles.

The price is $9.95 plus $2.95 S/H for a package of 4 drink markers in a variety of colors including a customizing sticker set.

Photo from Drinkmarx