Loon Deep Soft Weight is an eco-friendly, biodegradable replacement for lead split shot. You can select the exact size you want for each different rig and depth of water, and reuse the pieces so that nothing goes to waste. To use it, just pinch off a small piece and roll it onto the leader in the shape of a football. Dunk it in the water to harden it, and begin fishing. You can add and remove chunks as you fish to get your flies to the exact depth you want them in any pool, run, or riffle. Tungsten-based putty Biodegradable Reusable Non-toxic.