The tightener is divided into chain tightener and wire rope tightener. Chain tightener can be divided into tightener for binding goods when loading and tightener for overhead cables. As the name implies, the wire rope tightener is the tightener for wire rope traction. Comparatively speaking, the high-altitude tightener is more expensive and relatively durable. It is also called aluminum alloy chain hoist, the tonnage ranges from 0.75 tons to 6 tons, and the length of the standard chain is 1.5 meters, which can be made into a longer chain and made according to requirements. The aluminum alloy manual hoist cover is made of aluminum alloy, which has high hardness and light weight.