Overview Reviews Product Description EATON ECH666 EMT Compression Coupling Material: Zinc Plated Steel Size: 2 1/2 Inch Concrete Tight. Product Videos Custom Field Size 2-1/2 Material Steel Product Reviews Write a Review Write a Review × EATON ECH666 EMT Compression Coupling Material: Zinc Plated Steel Size: 2 1/2 Inch Concrete Tight Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Review Subject * Comments *