This is a genuine (not a Chinese copy) Tecomec "Made in Italy" blade balancer that has 6 magnets with large surfaces that ensures a perfect grip which allows for higher stability. The blade balance fits any size blade center hole up to 1-1/2". The balancer has a ball bearing spindle. Mounts right on the wall for easy use. Includes Owner's Manual. This blade balancer replaces Oregon model 42-047, Rotary 13216, Stens 750-050 and Maxpower 339075B. If you get on YouTube and search "TOOL REVIEW - Lawnmower Blade Balancer" by donyboy73 this is the exact same blade balancer we are offering in this listing. Check it out. Tecomec is an Italian company established in 1985 and is located in the Reggio Emilla region, this area is renowned worldwide for its top in quality technology. Tecomec is a company of the Emak Group which, in turn, belongs to the Yama Group with over 30 companies affiliates and represents the biggest Italian group engaged in the design, production and sales of farming, gardening and forestry applications.