Magnets blade balancer. It will balance any lawnmower blade with a hole in the middle. Replacement part number:339075B, 42-047 Made of high quality metal material,the thin metal rod to check the blades to see if they are bent,providing a smoother cut.When the blade is balanced, it will be horizontal. Please make sure there is enough space on either side when you mount your balancer,so that blades can rotate 360 degrees without obstruction and do not to hit anything. Colour:Red Material:Metal Package Contents: 1 * Blade Balancer Replace Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.