Erowa ER-007521 80mm Automatic EDM Chuck with a connecting rod. RHS version ER-007521 Rapid-action chuck automatic.ER-007521 compatible is useful for EDM sinking machines with automatic electrode change, machine tools with automatic loading, production lines. Product is made of 440C stainless steel, well rust-resistant. Clamping force up to 6000N with self-cleaning function.