A gas turbine aerofoil with at least one internal cavity for conveying cooling fluid through the aerofoil has at least one internal cavity adjacent the aerofoil leading edge, at least one impingement cooling passage extending from, and in flow communication with the cavity, and at least one film cooling hole extending from, and in flow communication with, the cooling passage. The configuration of the device permits multiples of the device to be loaded into magazines, which in turn may be loaded into and dispensed from high speed machine applicators to apply the devices to cans. The lock body can include a series of coaxial bores. An enclosure can extend above the base portion, the enclosure including a plurality of enclosure walls adapted to surround the container. Thereby, larger chromatic dispersion can be compensated while a decrease in transmission bandwidth is suppressed. The moving member is movable relative to the pulling member in a moving direction of the moving member in a case where the pulling member is inhibited from operating.