These brush blades can Compatible with OEM blades on select Husqvarna, Stihl,Oregon, and Hitachi trimmer models. They are also Compatible with other brands including Coocher Brush Trimmers, Dewalt Brush Trimmers, and as a Compatible with Forester brush blades. Please note that not all brands of lawn mowers are suitable. Please check the size of the adapter, as shown in the second and third pictures. If there are any compatibility issues, please contact us. 9’’ Chainsaw Tooth Steel Brush Cutter Replacement Blades and the Universal Fit Adapter: Fit most of the gas or electric trimmers with 10’’ X 1" arbor (25.4 mm) or 20 mm. These brush blades can Compatible with OEM blades on select Husqvarna, Stihl, Ego, Oregon, and Hitachi trimmer models. They are also Compatible with other brands including Coocher Brush Trimmers, Dewalt Brush Trimmers, and as a Compatible with Forester brush blades. Two Pack Different Adapter Kits: Blade adapter attachment maintenance washer First kit contains 1 x Thrust Washer/ 1 x Rider Plate/ 2 x different size Collar Nut/ 1 x Screwdriver/ 2pc x L-Wrench/ 1pc x T-Wrench/ 2pc x washer. The Second Kit: 1 x Thrust plate guard washer / 1 x Thrust washer/ 1 x Rider plate/ 1 x Lock nut/2 x washer. UNIVERSAL REPLACEMENT BLADE AND WASHER SET - Suitable for use on straight shaft trimmers, cutters, or weed eaters with an arbor size of 1 inch (25.4mm) or 20mm. Use with this included silver steel ring,you could attach the blade to 20 mm arbor. Diameter: 9 inches. Versatile, durable, and meets or exceeds OEM specifications, these brush blade kit can increase the parts' lifecycle by at least 50%. Cuts Like Butter: Our blades are great at cutting and pruning as you don’t have to put lots of pressure during the process, unlike other brands. Our blades are also approved by the mechanic to ensure the quality meets or exceeds the OEM and they help cut through thick weeds and brush in your back yard or other landscaping jobs. BE CAREFUL--- Highly recommend you wear boots or at least ankle-high shoes and jeans. The pieces of trees and rocks may bounce off of your leg. Safety glasses or goggles are necessary.If there is any problem with this Blade Set, please contact customer service in time, and you will get a satisfactory result. BE CAREFUL--- Highly recommend you wear boots or at least ankle-high shoes and jeans. The pieces of trees and rocks may bounce off of your leg. Safety glasses or goggles are necessary.If there is any problem with this Blade Set, please contact customer service in time, and you will get a satisfactory result.