The ALTRA INDUSTRIAL MOTION 642B is a classical sheave designed for A-B belt sections, featuring 2 grooves with a 6.75-inch outside diameter. It has a 1.3125-inch length thru bore and 1.75-inch face width, accommodating a bushing bore range of 1/2 to 2 inches. The overall width is 1-3/4 inches, constructed from durable cast iron material. Model: 6.4X2B-SDS.