Decibullz DIY Thermo-fit Molded Earpieces combined with new cutting edge percussive impulse filter technology. Decibullz Percussive Filters protect users from the peak sound pressure of gun shots artillery fire and explosions suppressing them to safe levels and protecting users from hearing damage. Custom molding is easy. Simply warm the earpieces in water and shape to your ears. The earpieces can even be re-heated and re-shaped if needed. Unlike electronic hearing protection Decibullz Filters never need batteries.