A fiber optic system includes a telecommunications chassis defining a front and a rear, a plurality of blades slidably mounted to the chassis, the blades slidable in a direction extending from the front to the rear, and a plurality of fiber optic cassettes removably mounted to each blade. Each fiber optic cassette includes a housing defining a maximum cassette height, the housing formed by a base and a cover mounted thereon. Each cassette defines fiber optic connection locations. The base of each cassette defines a notched area for receiving a portion of the blade on which the cassette is mounted such that the blade does not increase the overall maximum height defined by the housing.