Combination Metal and Rubber Jewelers Bench Block. What a great item. You can use the rubber or steel side. Addtionally, they come apart for separate use, however the rubber is less usefull as the metal bench block fits down inside of the rubber. The metal bench block measures about 3 3/4 inch x 3 3/4 inch x 3/4 inch thick. Combined, they measure about 4 inch x 4 inch by 1 1/2 inches thick. Not polished or perfectly smooth.