I purchased this as a spare repair part for a pressure cooker, but it's unused. When the lid's large gasket is fine but the "shush" sound stops, it often means air is leaking from this rubber part. The shape and size are different from the current mainstream ZK type, so they cannot be used interchangeably. This is a common part for the SW type Super Katsu-nabe 3.0L and can also be used without problems in shallow pots. Please refer to the manufacturer's website for details. It will be delivered in a Yu-Packet Post Mini envelope.