The Hermle 451 series clock movement is a chain driven, three weight, Westminster chime unit. This clock movement has square outer movement plates that are 120 x 120mm. What is being offered on this page is the movement only with out the pendulum, gong or dial. These movement come as the movement itself with its hand nut and new chains, also comes with the suspension spring and leader.
The numbers on the back plate of the movement is everything one needs to get a replacement. If the numbers match then the movement matches. If the clock is a pendulum unit, be sure to select the proper CM length that matches the old unit.
Prior to 1988, the year was two digits (79 was produced in 1979). Starting in 1988 the year of was indicated by a letter.