Each blister pack contains 4 pairs of tablets wrapped in foil.
One packet of tablets is sufficient to check your shot (diluted in 125 ml of water if used at full strength, or up to 250 ml).
For a search covering a 100 m distance, use the 4 packets diluted in 500 ml of water, or up to 1 L.

BlueStar comes in hermetically sealed foil packets that ensure a long shelf-life. Each packet contains two fast-dissolving tablets that only require some water to be ready for use. They are handy, efficient, and they won't load you down.
Any kind of water will work : river, pond rain, puddle...