The services gateway can have up to three SCBs. They are located in the front of the chassis in the slots marked 0 and 1 on an SRX 5600 services gateway and 0, 1, and 2/6 on an SRX 5800 services gateway. With a Routing Engine installed, the SCB weighs approximately 9.6 lb (4.4 kg).
Before you replace an SCB or a Routing Engine, you must power off the services gateway (see Powering Off the Services Gateway). To replace an SCB, use the following procedures: