A panel-mountable header connector comprising: conductors configured to transmit at least one of electrical signals or optical signals; and a housing holding the conductors in a cavity of the housing, the housing having a front end and a rear end, the housing having a latch set and a stop feature, the latch set being located between the stop feature and the front end of the housing, and the stop feature being located between the latch set and the rear end of the housing, the latch set and the stop feature defining a panel mounting zone therebetween, the panel mounting zone configured to align with an opening in a panel when the housing is mounted to the panel, the latch set configured to engage a front side of the panel and the stop feature configured to engage a rear side of the panel to retain the panel in the panel mounting zone, the stop feature being a flange, the latch set being stepped such that a width of the panel mounting zone is variable to accommodate the panel having one of multiple thicknesses, wherein the latch set includes at least one first panel latch and at least one second panel latch, the latch set being stepped such that a free end of the at least one second panel latch is disposed more proximate to the rear end of the housing than a free end of the at least one first panel latch, the free end of the at least one second panel latch or the free end of the at least one first panel latch being configured to engage the front side of the panel, characterized in that the flange includes at least one biasing segment along a front wall of the flange, the or each biasing segment including a lug that protrudes from the front wall, the at least one biasing segment defining at least one aperture that is axially rearward of the front wall, the at least one lug being at least partially deflectable and being configured to flex rearward at least partially into the at least one aperture, wherein when the connector is mounted to the panel, the at least one lug is configured to engage the rear side of the panel and to deflect at least partially into the at least one aperture to apply a biasing force on the panel towards the latch set. conductors configured to transmit at least one of electrical signals or optical signals; and a housing holding the conductors in a cavity of the housing, the housing having a front end and a rear end, the housing having a latch set and a stop feature, the latch set being located between the stop feature and the front end of the housing, and the stop feature being located between the latch set and the rear end of the housing, the latch set and the stop feature defining a panel mounting zone therebetween, the panel mounting zone configured to align with an opening in a panel when the housing is mounted to the panel, the latch set configured to engage a front side of the panel and the stop feature configured to engage a rear side of the panel to retain the panel in the panel mounting zone, the stop feature being a flange, the latch set being stepped such that a width of the panel mounting zone is variable to accommodate the panel having one of multiple thicknesses, wherein the latch set includes at least one first panel latch and at least one second panel latch, the latch set being stepped such that a free end of the at least one second panel latch is disposed more proximate to the rear end of the housing than a free end of the at least one first panel latch, the free end of the at least one second panel latch or the free end of the at least one first panel latch being configured to engage the front side of the panel, characterized in that the flange includes at least one biasing segment along a front wall of the flange, the or each biasing segment including a lug that protrudes from the front wall, the at least one biasing segment defining at least one aperture that is axially rearward of the front wall, the at least one lug being at least partially deflectable and being configured to flex rearward at least partially into the at least one aperture, wherein when the connector is mounted to the panel, the at least one lug is configured to engage the rear side of the panel and to deflect at least partially into the at least one aperture to apply a biasing force on the panel towards the latch set.