The chain of the gourd in the hand is galvanized chain, with shiny on the surface and not easy to rust. The aluminum alloy hand pull the gourd usually uses two specifications of 5 mm or 6 mm. In the case of the same load, the thinner the chain, the lighter itself. Light is more in line with the characteristics of aluminum alloy hand pulling gourd. Whether the distance between the chain is standard, whether it has been used for a long time is the impact of the opponent's gourd. The chain variable or wear is seriously changed in time. Otherwise, it will damage the gear inside the chain.