The Estwing Polyurethane Deadblow Sledge Hammers have power from within through the movement of hundreds of steel shot for maximum power and control. Steel canister, with steel shot, and steel handle are completely encased in polyurethane, which is oil and chemical tolerant. Eliminates or minimizes denting and marring. Reduces swing fatigue, sting and vibration. Protect your eyes from flying particles and dust. Always wear safety goggles. Bystanders shall also wear safety goggles.