Mitty 100/100 & 180/180: Perfect nail file kit Mitty nail files last 4 times longer than the average nail file and are extremely effective for rapid product reduction. Mitty 100/100 grit nail file can be used on builder gel, hard gel, acrylic, dipping (SNS) and all other form of nail extension. Whilst Mitty 180/180 nail file is perfect for nail preparation before nail extension or manicure. The Mitty Difference: Perfect for nail preparation and shaping of the natural nails Straight edge for