Crest 3D White Ultra White Whitestrips whiten tough coffee & smoking stains so you can flash an ultra-white smile The whitening strips gently remove up to 10 years of stains This excellent whitening tool is also safe on your enamel Crest Ultra White Whitestrips are easy to use – just apply it on your teeth, peel it off, and reveal your ultra-white smile Apply your strips for only 60 minutes a day to see noticeably whiter teeth in just 7 days (when used as indicated)! For best results, use up to 2 kits a year