An optic fiber system for mounting in a rack, cassette and front plate are disclosed. A fiber optic cassette receives a pair of opposed rails on opposite inner surfaces of a housing. Catches on the fiber optic cassette comprise biased tabs which engage grooves within the rails thereby releasable securing the cassette into the housing. Catches may be provided at both ends of the cassette allowing the cassette to be inserted from either end of the housing. The cassette comprises removable front plate which is secured to it using a snap fit. The removable plate can be used either with the cassette or as a standalone within the housing.