The primary purpose of the Screw Lid jars is for storage. The Screw Lid jars are compatible with the Familia Wiss closure system so can be used for preserving. Alternatively, just use the Familia Wiss Screw Lid to embellish the appearance of your storage jar. The Familia Wiss Sealing Caps and Screw Lids can be purchased separately. Hand wash only. The jar comes with a single 110mm plastic Screw Lid. 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.