The Soviets started assisting China inside manufacturing of ROMEO submarine in 1959. The Chinese variation is known as the kind 033 . The Chinese Type 033 incorporated some improvements on the original ROMEO, including sound reduction of at the very least 20 dB. An overall total of 84 Type 033 submarines were built-in Asia from 1962 to 1984, plus a few exported abroad. Today the majority of the Type 033 submarines have been resigned or preserved, with few remaining for training purposes.