About this item Whitens like a $500 professional level laser treatment Safe on enamel using the same whitening ingredient as dentists No slip teeth whitening strips Satisfaction 100% Guaranteed Apply once daily for 30 minutes for 20 days. Imported from USA. Get professional level whitening with Crest 3D White Whitestrips Professional Effects. They remove 14 years of teeth stains for a brilliantly whiter smile. Crest 3D White Whitestrips Professional Effects are like an eraser for your teeth. Youll see a whiter smile after 3 days, and full results in 20 days. Their no slip grip means the strips stay put until you take them off, allowing you to talk and even drink water while whitening your teeth.