1.High strength steel frame 2.The friction disc and ratchet as replacement parts,more convenient.Larger diameter of friction disc ensure reliable brake. 3.It on ratchet part.The performance of maintenance-free bearing is close to rolling bearing,better corrosion resistance. 4.The material is alloy steel,passed heat treatment.It includes stamping safety latch.The hook frame is forging with more reliable quality. 5.Opening style cover with curved edge,easy for hand chain replacement and smooth operation. 6.The ratchet cover fixed by support rod,effectively protecting brake system. 7.Load chain is alloy steel G80 according to ISO16877 8.Brake seat and driving shaft connected by screw thread,Driving shaft passed heat treatment with high precision dimension.