TWO BEARINGS: With 2 bearings, the rollers can rotate easily and never get stuck, which can prevent the rope from breaking due to excessive friction. Silent pulley: All parts are installed, seals are placed in the gaps, do not collide or make metallic noise. 600 kg load: The pulley is made of 304 stainless steel. Self-locking nut: Compared to ordinary nuts, it has the ability to resist loosening and vibration. 360° Swivel Ring: The block can be rotated 360° to prevent the rope from tangling. The maximum rope size is 10mm.