The cassette itself is comprised of four parts:
MTP brand/MPO adaptor(s) in back
MTP brand/MPO connectors to SC/LC fan out assembly inside the cassette
SC, ST, MTRJ (including keyed MTRJ), and LC (including keyed LCs) adaptors in the front
The cassette module body can be configured to multiple manufacturers for and fit factor.
By plugging an MTP brand/MPO cable into the back, you're lighting up 12 or 24 (with quad LC) connections. For the 24-fiber application, you can have either one 24-fiber MTP brand/MPO cable or two 12-fiber MTP brand/MPO cable or three 8-fiber MTP brand/MPO cables (plugging into two ports).
The cassette can be snapped into any standard fiber optic patch panel including both rack mount and wall mount. All it takes is one port! The panel can hold three of these cassettes which could potentially give you 72 active LC connections using only three (or six) MTP brand/MPO cables. Normally, you would have a patch panel that has straight-through adapter panels and would need dozens of duplex patch cords plugging into the back of them. Clean up the clutter and increase your possibilities using MTP brand/MPO cassettes.