Slidable fiber optic connection module with cable slack management

A telecommunications module comprising:

• a fixture;
• a fiber optic cassette mounted to the fixture via a first snap-fit interlock structure, the fiber optic cassette including:
• a body defining a front and an opposite rear and an enclosed interior;
• a fiber optic signal entry location defined on the body for a fiber optic signal to enter the interior of the cassette via a fiber optic cable;
• an adapter block defining a plurality of fiber optic adapters, the adapter block removably mounted to the cassette body with a snap-fit interlock, each adapter of the block including a front outer end, a rear inner end, and an internal passage housing a ferrule-alignment sleeve configured to receive opposing ferrules of fiber optic connectors that are to be mounted to the front and rear ends, respectively, and be optically aligned for continuing the fiber optic signal therethrough;
• a removable spacer mounted to the body defining the enclosed interior, the spacer configured to expand the size of the enclosed interior of the cassette;
• and
• a removable cover mounted to the spacer to enclose the interior;
• wherein optical fibers terminated with fiber optic connectors extend from the fiber optic signal entry location to the rear inner ends of at least some of the fiber optic adapters of the snap-fit adapter block for relaying the fiber optic signal to fiber optic connectors to be coupled to the front outer ends of the adapters;
• and
• wherein at least a portion of the first snap-fit interlock structure is defined by the adapter block.