FRONTIER-APPROVED PERSONAL ITEM SIZE: Fits perfectly under all airline seats (15.74"x12.2"x5.51") including Frontier Airlines personal item bag requirements. Save baggage fees with this lightweight carry on backpack for airplanes – slides effortlessly into overhead bins or seat compartments SUITCASE-STYLE PACKING WITH SECURE STORAGE: 180° full-open main compartment mimics luggage organization, featuring spring-loaded straps to lock clothes in place. Hidden anti-theft zipper pocket protects passports/cards against pickpockets during crowded airport transits TRAVEL SMARTER WITH LUGGAGE STRAP: Built-in luggage sleeve securely attaches to rolling suitcase handles, transforming this personal item backpack into a hands-free travel system. Walk through terminals or city streets without shoulder strain – your luggage backpack stays anchored to your suitcase BUILT-IN LAPTOP SLEEVE FOR WORK ON-THE-GO: Dedicated padded compartment fits 15.6" laptops and tablets, making this dual-purpose laptop backpack ideal for business trips or coffee shop work sessions between flights 360° QUICK-ACCESS ORGANIZATION: Front dual zipper pockets hold snacks/office supplies; stretchable side pockets carry 20oz water bottles or umbrellas. Separate your phone charger from toiletries – every item in this under seat bag for airplanes stays neatly sorted