Weight Core 2,000 grams 40 x 264 mm weighs 2,000 grams and measures 40 mm in diameter by 264 mm in length. Weight Core 264 mm fits weight shell number 79-653. Used for FHS 1151 chain movement with wooden pendulum or Lyre pendulum below 165 mm in diameter, for both time and strike side. Used for FHS 1151 chain movement with second hand feature and / or Lyre pendulum above 165 mm in diameter strike side.