2% Tincture of Iodine in a 10ml bottle with a nylon roller-top.

Over 100 tests per bottle.

The Iodine Test 
Buy an Iodine Roll-On and paint a 2" square spot on your inner arm . If it disappears in less than eight hours, you desperately need iodine. If it disappears in 24 hours, you also need iodine. If it simply stays on your arm and begins to slowly fade in color after a full 24 hours, you have already reached iodine sufficiency.