The primary purpose of the Super jar is for bottling preserves – but is widely used for storage as well. The Super range has a bulbous shoulder which assists with packing whole fruits and vegetable ready for preserving. Hand wash only. When closing a clip top jar, ensure that the lid is centred in the opening and apply downward pressure before clipping down the lid. The jar comes with a single 100mm natural Rubber Washer. The wire cage is made of stainless steel. The tempered glass is suitable for use in a water bather or pressure canner (i.e the vessels for sterilising low acid foods and hermetically sealing the jar) and hot-packing. Extra Rubber Washers can be purchased in packets of 10.