SK11 Hex Shank Diamond Sharpener #400/#1000 Double-Sided 50mm #400 Coarse Surface #1000 Finishing Surface For polishing carbide products, glass products, ceramics, blades, etc. with an impact driver. ＜Specifications＞ 6.35mm Hex Shank Grit: (Coarse Surface) 400, (Finishing Surface) 1000 Compatible Models: Electric Drill, Impact Driver #400 has been used a few times. #1000 has not been used. I am not considering lowering the price. I would appreciate it if those who understand that this is a used item would purchase it. Thank you very much.