Regula 34/46 Mvmt is an 8 day cuckoo movement with dancing platform (81 mm high, measured from above the handshaft) that has a pendulum length of 23.5 cm, a plate size of 85 mm by 76 mm and requires 3 weights of 1500 grams each (can be purchased separately). Regula 34/46 Mvmt comes complete with a bird rod, chains, stop rings, weight hooks, hand nuts and an extended post for music activation lever. Regula 34/46 Mvmt should be used with part # 72-5874 to engage the music unit with the music chain gear on the movement.