Cartridge seals are complete seal units that contain a gland, flush ports, sleeve, seal faces, o-rings, set screws, and gaskets. They are the simplest mechanical seals to install and most reliable due to being a self-contained unit. The document then provides specifications and pricing for various sizes of cartridge-style mechanical seals from 1" to 4" made by ASP and notes they can be installed without modifying most ANSI pumps with a 1-1/2" deep stuffing box.