This 9" x 20T Carbon Steel Round Chainsaw Tooth Brush Blades & 9"x36 Teeth Carbide Tipped Blades has a 1-inch(25.4mm) hole in the center, which is suitable for most straight shaft gas trimmer with 1 inch(25.4mm) gear case. There are two different adapters that can be used for more models of lawn mowers.

The brush cutter kit and Universal Fit Adapter for brands - Husqvarna/ Stihl/ Oregon/ Hitachi – They are also Compatible with other brands.The weed eater blades metal is made of manganese steel, and the insert has high hardness and long service life. Trimmer head suitable for cutting branches, brush and shrubs.

Please don't let the blade hit stone and other solid objects, the blade will be blunt or even damaged. The weed trimmer head is very easy to install, Just need to connect weed trimmer head to the shaft punch of the mower, it can be quickly and easily assembled and disassembled.（Please follow the fourth picture to install）

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/1 x glove.

One year warranty, 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.