The 4pcs adapters are nice accessories for weed trimmer head, applicable to most models. Specifications: Material: Steel Collar nut diameter: 25mm / 0.87in Thrust washer diameter: 42mm / 1.65in Rider board diameter: 73mm / 2.87in Package Weight: 150g / 5.29ounces Package Size: 80 * 80 * 50mm / 3.15 * 3.15 * 1.97in Replacement parts are as follows: Thrust washer: 4130-713-1600; Knight plate: 4126-713-3100; Collar nut: 4126-642-7600. Replacement for FS120 FS130 FS130R FS200 FS200R FS250 brush cutter. Packing List: 1 * Thrust Washer 1 * Knight Board 1 * Lock Nut 1 * Thrust Plate Protective Washer