4-way Nail Buffer.

Shape, smooth, buff, shine—this multi-tasking buffer lays the groundwork for a perfect manicure and is also a tool for a quick fix for high-shine on the go without nail color. The extra gentle, microfiber material is easy on the nails.  
Use the numbered sides of Smooth Operator as follows:

1. Gently shape nail tip.

2. Gently buff ridges on top of nail.

3. Smooth nail surface before applying base coat.

4. Buff to high-shine when you don't want to wear nail polish. Do not buff to high-shine if you intend to paint your nails.