The Eastman Flexible Coupling 4" x 4" 86010 is a black, rubber and metal coupling designed for connecting two pieces of equipment or machinery with a 4" x 4" inch system of measurement. It features a 6" x 6" item length and is compatible with other Eastman couplings, specifically model 86009. This high-quality product from Eastman is perfect for various industrial applications requiring flexible and durable connections between components.