A system, comprising an autonomous seismic node for deployment to the seabed and an external device, the autonomous seismic node comprising: a pressure housing for an autonomous seismic node, wherein at least one seismic sensor, at least one data recording unit, and at least one clock are located within the pressure housing, wherein the autonomous seismic node is configured to land on the seabed; and a bulkhead connector coupled to the pressure housing configured to receive an external device, wherein the bulkhead connector comprises: a cylindrical housing that forms an inner cavity and a connector insert, wherein the connector insert comprises: a flat contact surface; and a plurality of pins configured to transfer power or data with the external device, wherein each pin comprises a flat electrical contact surface configured to be substantially flush with the flat contact surface, characterised in that: the external device comprises a sealing element (528; 728); the bulkhead connector is configured for subsea use; and the inner cavity is configured to receive said sealing element (528; 728) located on the external device. an autonomous seismic node for deployment to the seabed and an external device, the autonomous seismic node comprising: a pressure housing for an autonomous seismic node, wherein at least one seismic sensor, at least one data recording unit, and at least one clock are located within the pressure housing, wherein the autonomous seismic node is configured to land on the seabed; and a bulkhead connector coupled to the pressure housing configured to receive an external device, wherein the bulkhead connector comprises: a cylindrical housing that forms an inner cavity and a connector insert, wherein the connector insert comprises: a flat contact surface; and a plurality of pins configured to transfer power or data with the external device, wherein each pin comprises a flat electrical contact surface configured to be substantially flush with the flat contact surface, a pressure housing for an autonomous seismic node, wherein at least one seismic sensor, at least one data recording unit, and at least one clock are located within the pressure housing, wherein the autonomous seismic node is configured to land on the seabed; and a bulkhead connector coupled to the pressure housing configured to receive an external device, wherein the bulkhead connector comprises: a cylindrical housing that forms an inner cavity and a connector insert, wherein the connector insert comprises: a flat contact surface; and a plurality of pins configured to transfer power or data with the external device, wherein each pin comprises a flat electrical contact surface configured to be substantially flush with the flat contact surface, a cylindrical housing that forms an inner cavity and a connector insert, wherein the connector insert comprises: a flat contact surface; and a plurality of pins configured to transfer power or data with the external device, wherein each pin comprises a flat electrical contact surface configured to be substantially flush with the flat contact surface, a flat contact surface; and a plurality of pins configured to transfer power or data with the external device, wherein each pin comprises a flat electrical contact surface configured to be substantially flush with the flat contact surface, the external device comprises a sealing element (528; 728); the bulkhead connector is configured for subsea use; and the inner cavity is configured to receive said sealing element (528; 728) located on the external device.