Abstract: A cannula top for enclosing a surgical seal which comprises a base member having a through bore which defines a receptacle for the surgical seal and a lid member having a through bore. The lid member is movable between a first position in which the surgical seal can be inserted into and removed from the receptacle, and a second position in which the surgical seal is engaged by the lid member and retained in the receptacle by the lid member. The cannula top further comprises a connecting member which connects the lid member to the base member in both the first position and the second position.