Ah, the ever popular backpack. Thank goodness for Asher ‘Dick’ Kelty, who invented the handy carrier back in 1952, as well as Greg Lowe, who invented the internal-frame packs in 1967.

Before the backpack came to be, students were literally carrying around their books with a single strap of leather or cloth that fastened to them. When the backpack made its debut, everyone from students to hikers and more has been able to carry heavy loads with ease.

Of course, backpacks have greatly since evolved since the 50s. Nowadays, some contain hidden compartments or more sections than others. Some are made out of different materials, have different designs, or have varying purposes.

Depending on what your needs are or what your body type is, you’ll probably take all these different features into consideration when choosing the one. For example, a camper probably won’t need laptop sleeve, whereas a student might not need a walking stick carrier.

While backpacks differ greatly, there’s one feature you might’ve noticed on a lot of them recently. We’re talking about that weird leather patch with two slits in it—yes, the one that kind of looks like a pig’s snout.

“Pig’s snout” is actually one name for the patch—but it’s most commonly called a “lash tab,” and it isn’t just there for looks. It’s most commonly seen on backpacks made by Herschel Supply Co., Jansport, and L.L.Bean, three of the most popular backpack brands. And it actually has this really cool purpose you might’ve not known about.

What is a lash tab used for?

The lash tab is there so that you can pack even more than what fits inside your backpack—because you can pack items outside of your backpack using the patch.

Mind. Blown.

So for example, sneakers won’t fit inside your bag? Thread the laces through the slits and tie it to the opening of the lash tab. If the object doesn’t already have something you can tie to the slits, you can just fix that object to a string and voilà! Ready for the lash tab. Once you thread that object through the slits, you can secure it with a knot or even duct tape or a staple.

The lash tab is not only useful for taking extra items with you, but also for easy access to things you need most. For instance, headphones are a great item to put there (especially if yours get lost on the bottom of your bag. Worst.) Fun fact:

The lash tab was originally created to carry an ice ax, the co-founder of Herschel & Co., Jamie Cormack, said in an interview with TODAY Style. Apparently backpackers would thread webbing through the slots of the lash tab, hang their ax from it, and keep it secured with a tension lock. Now that you know what a lash tab is, what are you going to use it for? For some ideas as well as more info on how to use it, be sure to check out the video below!