Product  features:1.outercovershell thickening design,increase the convex  reinforcement process,impact  resistance,effective  protection  of  internal   transmission    mechanism.2.hand   wheel cover adopts the crimping process to increase the strength  and  avoid  the  clasp  and  great  noise.3. gear  adopts   high   quality  alloy  steel   precision  forging    processing,and    after    heat    treatment  durable,reflect  high   transmission  efficiency.4. hook   adopts   high   quality   alloy   material,after  special   heat   treatment,improve  safety  warning, and do not break when overload.