A keystone module is a standardized snap-in package for mounting a variety of low-voltage electrical jacks or optical connectors into a keystone wall plate, face plate, surface-mount box, or a patch panel. Keystone modules have a rectangular face of 14.5 mm wide by 16.0 mm high and are held in place with flexible tabs. This allows them to be snapped into a mounting plate with correspondingly-sized rectangular holes, called ports.
The RJ45 connector is standardized as the IEC 60603-7 8P8C modular connector with eight conductors. The 8 position 8 contact (8P8C) connector is a modular connector commonly used to terminate twisted pair and multi-conductor flat cable. These connectors are commonly used for Ethernet over twisted pair, registered jacks and other telephone applications.
This RJ45 keystone, a pass-through type connector, is interchangeable, replaceable and provides much flexibility in arranging and mounting many different types of electrical jacks in wall plate or outlet panel without requiring customized manufacturing