Each sand No. features: 
<br />No. 150: coarse sand, polish fast for long fingernails rapid wear short  Gum handle, elastic moderate 
<br />No. 180: medium sand, the grinding rate is moderate, moderate sophistication  Gum handle, elastic moderate 
<br />No. 240: fine sand, grinding slower, more delicate  Gum handle, elastic moderate 
<br />No. 100/180: relatively coarse sand, suitable for people who nail surface texture depth 
<br />No. 220/280: sand is relatively thin, fit people pale nail surface texture 
<br />No. 1000/4000: suitale for use in nail polish, used the same as using too bright and shiny oil
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<br />Packing Content:
<br /> 6Pcs Nail files (as the picture showed)