Black Box KVM Extender Housing ChassisBlack Box KVM Extender Housing Chassis The Black Box KVM Extender Housing Chassis is a versatile, modular solution designed to consolidate KVM extender boards in a compact, scalable footprint. Available in desktop configurations that can house 2, 4, or 6 boards, and a robust 19 inch, 4U rack chassis capable of accommodating up to 21 boards, this family delivers flexible deployment for small workstations up to large data center style installations.