Auto Beat Escape Wheel FHS 451 52 to 75 cm is an escape wheel specifically for Auto Beat Movements 141, 151, 241, 351, 451, 1051, 1151, 1161, and 2061. Auto Beat Escape Wheel 52 to 75 cm is for movements with a pendulum length of 52, 66, 75 and 114 cm. Pendulum length is indicated on the plate of the clock, it is not the actual measurement of the pendulum.