A method of attaching a device to an endoscopic device, comprising: providing an adapter for attaching a device to the distal end of an endoscopic instrument , the adapter comprising: a distal stop to limit penetration of the endoscopic instrument into the adapter ; and at least one flange projecting axially from the distal stop and comprising: a non-closed perimeter, the flange configured for insertion of the endoscopic instrument therein, the flange having at least one longitudinal opening ; attaching a device to be transported to said adapter ; attaching said device to said endoscopic instrument ; characterized in that , the adapter further comprises a securing means , releasably attachable to the flange , to compress the flange against the endoscopic instrument to secure the adapter to the endoscopic instrument to prevent motion of the adapter with respect to the endoscopic instrument , the securing means , when attached to the flange , at least partially wrapping around the flange , and configured to span the opening of the flange and to at least partially wrap around the endoscopic instrument ; wherein the flange includes an expandable flange portion defining the longitudinal opening and a highly expandable, generally optically clear, sealable membrane portion with sufficient folded-back or serpentine geometry to accommodate the insertion of an endoscopic device having a diameter greater than that of the distal stop , the membrane portion covering the opening, and the securing means configured to span the membrane portion and the opening. providing an adapter for attaching a device to the distal end of an endoscopic instrument , the adapter comprising: a distal stop to limit penetration of the endoscopic instrument into the adapter ; and at least one flange projecting axially from the distal stop and comprising: a non-closed perimeter, the flange configured for insertion of the endoscopic instrument therein, the flange having at least one longitudinal opening ; a distal stop to limit penetration of the endoscopic instrument into the adapter ; and at least one flange projecting axially from the distal stop and comprising: a non-closed perimeter, the flange configured for insertion of the endoscopic instrument therein, the flange having at least one longitudinal opening ; attaching a device to be transported to said adapter ; attaching said device to said endoscopic instrument ; characterized in that , the adapter further comprises a securing means , releasably attachable to the flange , to compress the flange against the endoscopic instrument to secure the adapter to the endoscopic instrument to prevent motion of the adapter with respect to the endoscopic instrument , the securing means , when attached to the flange , at least partially wrapping around the flange , and configured to span the opening of the flange and to at least partially wrap around the endoscopic instrument ; wherein the flange includes an expandable flange portion defining the longitudinal opening and a highly expandable, generally optically clear, sealable membrane portion with sufficient folded-back or serpentine geometry to accommodate the insertion of an endoscopic device having a diameter greater than that of the distal stop , the membrane portion covering the opening, and the securing means configured to span the membrane portion and the opening. <EOS>