SNS stands for Signature Nail Systems. It's a powder dipping system accompanied by a brush-on, gel-based polish. The nail technician will apply the polish to your nail, dip it in the powder and repeat the process.
SNS comes in an array of whites, pinks and hundreds of other fun colours. SNS actually consists of the organic chemicals Benzoyl Peroxide, Titanium Dioxide, and Acrylic Ester Polymer. These work to lengthen and add strength to your nails rather than wear them down.