Dimensions: 50 x 47mm (DL) suitable for most electric drills, designed with convenient and practical prefect spinning scale Strong material: made of whetstone and steel, enough strong and durable to give your trimmer a clean and sharp edge again and can serve you for a long time Easy to use: Buth hand and hand drills can be used, sharpen the blade easily and quickly. The blade balancer is designed to fit 99% of all center holes. Efficient tools: perfect for sharpening lawn blade, drill blade, trimmer, cutter trench bar, rotary cutters, hoe, etc., make the cutting edge more efficient Package includes: 4 pieces of lawn blade sharpeners in blue + 1 piece of blade balancer. Note: Quite heavy so be careful when using!