Cobra Pro Hardener Essential Activator for All Cobra Pro Bedliners Cobra Pro Hardener is the critical component that brings your Cobra Pro Bedliner to life — delivering the chemical strength, adhesion, and durability required for long-term surface protection in the harshest environments. How to Use Mixing Ratio: 3 parts Cobra Pro Bedliner : 1 part Cobra Pro Hardener Designed to be used exclusively with Cobra Pro and Cobra Tintable systems ⚠️ Application Warning This product is part of a permanent coating system. If you're unsure how it will interact with your surface, always test on a disposable area first. Once applied and cured, the coating cannot be removed. 💡 Need help mixing or applying? Visit our FAQs or HOW TO section for step-by-step guides and expert tips. Lock in Toughness. Cobra Pro Hardener – Built for unbeatable adhesion and protection.