Acrylic Disk or plastic lid for Jam jar
Thin Aluminium foil
50mm Bolt & nuts
Drill a hole in the centre of the plastic lid for the bolt to go through. Saw a slot in the screw end of the bolt. Place the bolt through the plastic lid and bolt in place leaving 20mm of bolt and the bold head sticking out. Glue two thin sheets of aluminium foil 30mm long and 10mm wide from a chocolate wrapper into the slot ensuring that the foil is not glued together. Replace the lid on the jar and secure.