Earlier this year, I went to Chicago with a friend and was instantly jealous when I saw her travel backpack. I'd picked up a plain backpack at Marshall's, but she was using the Beis Backpack. When I watched her unzip it all the way, I knew I needed that bag.

Fast forward to my birthday, I got the Beis bag as a gift. I really got a chance to put it to the test a few weeks after my birthday on a trip to Dollywood. In an effort to save money (but possibly cause insanity), I booked my trip on three different airlines and really put this bag to work. It turns out, this is the best bag I've ever used as a carry-on.

There's a sleeve on the back of this backpack that you can slide over the handle of your rolling lugge for easy travel.

It was a bit of fate getting this bag for my birthday because Beis is a company founded by actress Shay Mitchell and she's my birthday twin. As an actress and vacation aficionado, Mitchell was inspired to create a brand that fellow travelers would enjoy. 

"After countless trips and #Shaycations, I realized that I wanted to create amazing, affordable pieces for travelers like myself and — in turn — everyone inspired to seek new places, meet new people and share the world.” 

Beis sells backpacks, weekender bags, work totes, travel totes, baby bags, and luggage of all sizes.

On the first United flight, the bag fit under my seat but stuck out a little (the flight attendant didn't seem to care or notice). On my second flight, I was on a tiny plane and the bag was too large for under the seat, so it went overhead.

The Backpack (also called the Daytripper) is a budget-friendly offering from Beis. It is just under $80 and can act as a personal item and/or carry-on bag when flying. I used it as my personal item and had a roller luggage from Away as my carry-on bag.

Measurements: 13"" W x 19"" H x 5.5"" D Weight: 1.8 lbs Capacity: 22L

I brought this bag on three different airlines (United, Delta, and JetBlue) and a total of five airplanes. My first two flights were on United, on a Boeing 737-900 Twin Jet and Embraer EMB-145XR Twin Jet. On the 737, the Beis Backpack fit under the seat but poked out a little bit. The EMB was essentially a puddle jumper. The row I was in on that flight was only one seat per row instead of three. On the flight, the backpack was much too large to fit under the seat, so it had to go in the overhead bin. It fit in there sideways.

The next airlines I used this bag on were Delta and JetBlue. The bag fit under the seat on the Delta plane (a CRJ-200), but it was hard to get the bag out when deplaning. The Beis Backpack fit the best, plus gave me legroom to spare on both JetBlue planes (a E190 and a A21N). I had to turn the bag sideways on the first plane, which is something I couldn't have done on the Delta or United flight. Of the three airlines, this bag was best suited for the JetBlue planes, but it fit (one way or another) on all three. 

I knew this bag would fit a lot, but was still impressed when I packed it. You can unzip the main compartment all the way to get maximum storage. I was able to stuff two other bags inside of it (two hiking packs), an extra pair of shoes, several changes of clothes, and all of my travel essentials like medicine, gum, my phone charger, and ID. I really did not want to check a bag, since I was flying on multiple airlines, and having this as supplemental luggage made it easy to just carry on my items.

The number of pockets and elastic compression straps made this easy to organize everything inside of my bag. The large front pocket also made it simple to grab items I needed during the check in process at the airport. I didn't have to dig around my bag to find my license, as I was able to store it right in front.

I was nervous that filling this bag up so much would make it uncomfortable to wear. I was pleasantly surprised to find that filling this bag to the absolute brim did not make it painful to wear. It barely even felt heavy. Not even when I lugged it around Dollywood all day filled with sunscreen, souvenirs, an extra pair of shoes, and everyone's water bottles. 

This bag is currently only available in two colors: black and beige. Previously, it was sold in a limited edition olive color (which my friend had and I wanted most). For folks who like neutral colors, this isn't a big deal. I think maybe two or three more color options that aren't limited edition would be nice for variety. 

This bag barely fit under the seat on my Delta flight. Thankfully, I did not feel cramped while sitting on the plane. I didn't really notice how small the seats were until I tried to get off the plane. My bag was very stuffed because I was leaving vacation with extra Dolly Parton shirts and souvenirs. When I pulled my bag up, the plane seat began to detach and come up with the bag because it was such a tight fit. This didn't happen on my JetBlue or United flights. 

The Backpack fully unzips, which is a key feature for packing. You can see every inch of space when filling this up.

While I was very intrigued by the backpack, because when you've seen one roller bag, you've seen them all, there are three other bags that are bestsellers at Beis. Even more popular than the Backpack is the Weekender Bag. And of course, since Shay Mitchell is a mom (and expecting her second child any day), Beis has an excellent Baby collection.

Ana Suarez is the senior commerce editor for Hearst Newspapers. She is always on the hunt for good sales, but really, she just won't shut up about her senior dog, Tyrone.