Neon Wax Sighter is a product developed out of necessity.
When euro nymphing, you usually try to keep full contact with your fly for as long as possible by keeping your rig tight. Neon wax can be used to mark your leader to assess how deep the fly is in the water column. By drifting the nymph at different marker depths, you can easily locate the depth of where fish are holding.
Multiple markings can be used on the leader to help assess whether to raise or lower the fly.
Additionally, use Neon Wax Sighter on tippet above a small or dark colored dry fly, which are normally easy to lose sight of.
Neon Wax Sighter will not permanantly stay on your leader. The most effective temperature range for adhesion is 50 - 85 Fahrenheit. Below this temperature, the wax is brittle. Above this temperature, it will begin to melt. (If you leave this in a hot vehicle, you can expect a mess when you return.)
Use Pink or Orange for bright sunlight, Lime or Green when the sky is overcast, and for heavily fished water, use white for dark colored river bottoms and black for light colored river bottoms.
Stains in clothing can be washed with detergent or soap. Easily removed from leader and tippet with a tissue paper.