Fungi-Nail Toe & Foot Pen applicator provides a no-mess, no-spill, targeted treatment and delivers the right amount of treatment right where you need it. The solution contains 25% Undecylenic Acid, the maximum strength available without a prescription, Fungi-Nail Toe & Foot guarantees visible results in 4 weeks. This anti-fungal treatment is ideal for treating toe and foot fungus. It eliminates fungal infections on cuticles, around nail edges, and under nail tips.