Normal WW2 and Korian War period, normal for this period bottle contains Thio. Tablets.The Diggers Water Bottle had to be completly emptied then refilled with the water available, then the tablets added after crushing according to the instructions inside the lid. This enabled the Digger to drink his water in the surity that he would not pick up a problem from the contaminated water that may have been his only liquid available. These tablets have been produced by science to keep the diggers in top fighting condition. Not rare but everybody both male and female (Nurses etc.) would be issued with this tin of tablets.60 X 18 mm glass bottle with cork 11 X 17 mm and cotton wool, contains 50 blue Thio tabletsMarked on bottle in blue paint, 50. Thio. Tablets. Drug Houses of Australia Ltd. Australia. bottle from sterilizing outfit outfit. contains blue tablets, ww2, new guinea, korian war, borneo, boganville etc., etc