You can only front (flush) mount the Cisco MWR 1941 router in a 19-inch (48.3-cm) equipment rack that conforms to the EIA-310-D specification. The rack-mount brackets are slotted to allow the router to be mounted in racks with EIA 1.25-inch (3.81-cm) or WECO 1.0-inch (2.54-cm) hole spacing.