Spirit Airlines announced Tuesday that it will charge its customers $20 to $45 for items they place in the overhead bins.

The cost depends on whether passengers are members of the airline’s ultra-low fare club and whether they “pre-reserve” their carry-on bag in advance.

Each passenger will still able to bring one personal item that fits under a seat for free, such as a purse, briefcase, backpack or laptop computer. They also won’t have to pay extra for items such as diaper bags, pet containers and cameras.

Airline officials called it a “bring less; pay less” policy that would ultimately benefit customers.

Spirit’s new fee is effective for reservations made after April 5 for travel starting August 1. Although it’s already among the airlines that charge for checked bags, the ultra-low-cost carrier is the first carrier in the United States to implement a fee for carry-ons. It may also be the first airline in the world to do so, said Genevieve Shaw Brown, senior editor at Travelocity.

Spirit, which is headquartered in Miramar, Florida, and flies to destinations in the U.S., the Caribbean and Latin America, says it keeps costs low by starting with rock-bottom fares and asking passengers to pay only for the optional services they want.

Spirit’s new fee structure had industry observers wondering whether other airlines would follow. Shaw Brown called it a “very, very bold move” and predicted that Spirit’s competitors would be watching the fee’s failure or success very closely.

Others wondered whether it signals even more drastic changes for passengers.

(Read more at CNN.com)