Threaded or like caps or cap-like covers secured by rotation engaging a threaded ring clamped on the external periphery of the neck or wall {engaging a bung-ring clamped on the neck or in the wall}
Threaded or like caps or cap-like covers secured by rotation engaging a threaded ring clamped on the external periphery of the neck or wall {engaging a bung-ring clamped on the neck or in the wall}