Forged chain , 1. type X458,X348,X678 with trolley 2. type : 55,57, 77 forged chain 2. made of 40Cr material Forged chain :1. type X458,X348,X678 chain with trolley2. type : 55,57, 77 forged chain 3. made of 40Cr material4. manufactured by Hangzhou Vision Chain Transmission Co.,LtdDrawing: Products &Equipment: Certification: About TV Chain: