This unit is Center Mount If you are unsure how to tell the difference please see our help section. Type D Movement - Synchron synchronous motor clock movements provide for a sweep second-hand and split-second accuracy for either consumer, industrial or laboratory clocks and time keeping applications. The "D" movement uses aluminum plates for a simple clock movement with smooth continuous running. These precision electric movements are designed and built to give sustained split-second accuracy in clocks ranging from the daintiest bedroom style to glass display clocks up to 26 inches (660 mm) in diameter. Center shaft overall length 2 5/8"...