Material: Strong and durable plastic. High durability: Reusable lock washers, durable fastening outdoors and in greenhouses. Length: approx. 6.8 * 6 cm - Black, package included: 100 pieces of lock washers. Keep the fabric safe: Ideal for keeping garden netting down, protecting tarpaulins and grass edges on garden fabrics, awnings, brushes, ponds, flower beds, seed, litter boxes, not only can they perfectly secure the four corners of the turf, but also make it easy to pull out.