A mated connector assembly includes: a first connector assembly, comprising a plurality of first coaxial connectors mounted on a substrate, each of the first coaxial connectors connected with a respective first coaxial cable, and further comprising a latch pivotally mounted to the substrate, the latch having an arm with a free end; a second connector assembly, comprising a plurality of second coaxial connectors and a shell, each of the second coaxial connectors connected with a respective second coaxial cable, the shell defining a plurality of electrically isolated second cavities, each of the second coaxial connectors being located in a respective second cavity and mounted therein to float radially and axially relative to each of the other second coaxial connectors; wherein a slot is present is the shell, the slot providing access to one of the second cavities from outside the shell; wherein in a mated condition each of the first coaxial connectors is mated with a respective second coaxial connector; and wherein the latch is pivotable between an unlatched position, in which the free end of the arm is absent from the slot, and a latched position, in which the free end of the arm of the latch extends through the slot and engages a second coaxial connector; and wherein the first and second connector assemblies are secured in the mated condition by the latch when the latch is in the latched position.