PACKAGE INCLUDE: 4 pieces of lawn mower blade sharpener and 1 piece of lawn mower blade balancer for 42-100 model. SIZE: diameter 50mm/1.97, length 47mm/ 1.85, suitable for most electric drills, designed with perfect balance of rotation, convenient and practical. SOLID MATERIAL: Made of whetstone and steel, strong and durable enough to make your trimmer again a clean and sharp edge, and you can reuse it many times times. EASY TO USE: Both electric drill and hand drill can use it, it can sharpen the blade easily and quickly. The blade balancer is designed to fit 99% of all center holes. . EFFICIENT: Ideal for sharpening lawn mower blade, drill blade, lawn mower, scythe, tillers, etc., to make edging more efficient. NOTE: Quite heavy so be careful when using it! .