A valve component (1) of the invention comprises a main valve (2) which is located on a centre line and at least one auxiliary valve (3) which is located radially outwardly of the main valve (2). The main valve may be used for sealing engagement with a cannula. In some cases the cannula may be used for introduction of a number of robotically controlled surgical instruments generally, including a camera. The auxiliary valves (3) may be utilised to introduce another instrument through the valve component. The valve component is mounted in a manner which ensures that the valve component (1) is rotatable about a centre line through the axis of the valve component (1). This ensures that the valve component (1) can be rotated relative to a cannula inserted through the main valve (2) and consequently that the auxiliary valves (3) are rotatable relative to the cannula allowing the auxiliary valves (3) to be positioned to facilitate optimum access and manipulation for an auxiliary instrument(s) inserted through the auxiliary valve(s) (2).
