Kilner Wide Mouth Preserve JarPreserve your favourite fruits and vegetables in this 350ml preserving jar. Designed for functionality and practicality, this preserving jar is designed with a metal screw top lid to vacuum seal your ingredients for a longer outcome. To vacuum seal your jars, immerse your closed jars in boiling water for 30 minutes, leaving it to simmer. Once boiled, allow the water and jars to cool completely before removing. Your vacuum sealed jars will preserve contents for up to 6 months if stored in a cool, dry place. For extra convenience, this preserving jar also features embossed measurements on the side of the jar when adding the filling. Specifications :350ml capacity. Made from glass and metal screw top.