Spirit Airlines is adding new middle seats to allow for extra leg room and an additional inch of width. The middle seat will be 18 inches wide, versus 17 inches for the aisle and window seats.

The design, from U.K.-based Acro Aircraft Seating, involves thicker padding, better lumbar support and an inch more pre-recline than its existing seats. The padding is made from lightweight foam to avoid adding weight to the plane.

Spirit also said it would no longer use the term seat pitch, the industry standard for leg room. CEO Ted Christie said most passengers did not understand the definition. Instead, Spirit will measure usable legroom, the distance from the center of the back of the seat cushion to the outer edges of the seat in front. By this measure, Spirit’s new middle seats give passengers an additional two inches of legroom.

Spirit consistently ranked at the bottom for customer satisfaction, likely due to its no-frills, stripped-down approach. The low-cost carrier has been investing in improvements to the passenger experience, though, including priority boarding schemes, new aircraft and a new website and app.

The airline is also changing its premium Big Front Seats product. These seats will have a new memory foam headrest, additional memory foam in the seat cushion and yellow and black stitching.

Spirit plans to release the cabin redesign plans in November, along with new branding.