Brand new and high quality. Inner diameter of housing 26mm. The gearbox has a 10 x 1.25 left hand male thread. Made of aluminum alloy + steel material, low density, high strength, strong conductivity. Universal lawn mower accessories gearbox head and full set of accessories. Product Description The difference between single ear and binaural working head (this product is single ear gear head) - Different clippers have different applicable working heads. Both the single ear / binaural work heads are universal, but the mounting screw hole locations are different. If they do not match, you must drill the holes yourself (it is recommended to purchase the type of work head you used previously) When installing the workhead, do not overtighten the set screws. Overtightening may damage the workhead. You need to add oil before use, and add oil every 10 hours or so, otherwise the gear inside is easy to be damaged. Features: High Quality: The inside diameter of the case is 26mm. The gearbox has a 10 x 1.25 male left-hand thread. Made of alloy aluminum + steel material, low density, high strength, strong conductivity. Universal lawn mower accessories, gear heads and full set of accessories. How to determine the product model (There are two steps) Step 1: Count the teeth in the counting tube or count the teeth of the drive shaft to confirm (7 teeth) Step 2: Measure the inner diameter of the pipe or measure the diameter of the aluminum pipe to confirm (26mm) Work head shell Built-in work head housing, effective protection of the integrated bearing. Bearing High quality bearings, wear-resistant and durable. Blade mounting hole Blade mounting hole design, convenient and safe. Thickened shell Full protective cover, high hardness and not easy to deform.