Size:20mm About the product: -High quality, solid and resistant. - The single pulley block can be rotated 360 degrees to prevent ropes/cables/knotting for convenient use. - Single pulley for many applications: garage, machine loading, curtain, clothesline, dog pulley system, etc. Specifications: Material: high quality 304 stainless steel. Size: approx. 75*25mm. The package includes: 4 pieces M20 single pulley.Note: If you receive a product with defects in materials or workmanship,we will replace or refund it. Note: The data are all manual measurement, please allow 1 - 3cm error, due to the Light and display difference, there will be a certain color difference, depending on the physical object received Delivery Quantity: (according to the main image)