Perfect kits for your Stihl String Trimmer. What You'll Get: Blade adapter attachment maintenance washer kit contains 1 x Thrust Washer, 1 x Rider Plate,1 x Nut, 1 x Bevel washer ,1 x Screwdriver, this does exactly what it should and is well constructed Thrust washer:4130-713-1600;Rider plate: 4126-713-3100;nut:4126-642-7600. Gardening Machine Lawnmower Kit Size: Screwdriver size: 128 mm/ 5.0inch, Rider plate diameter: 80 mm/ 3.15 inch, Nut Diameter: 25 mm / 0.98 inch, Thrust Washer Diameter: 42 mm/ 1.65 inch. Please Do Check The Size of Blade Adapter Kit before placing the order. Easy to Install: Easy to replace the string spool on the trimmer with the stihl blade adapter kit. The blade fit tight and there was very little vibration. Package Includes: 1x Blade Adapter Attachment Kit