Now that crest has different kits we will focus on the Supreme that is the strongest aimed at heavy tooth discoloration with people with yellow teeth. You have 21 days and a lot longer top and shorter bottom strip and are a single layer. The 3D is a 20 day but not as strong as supreme but its still pretty strong. The third is the advance vivid its the same strength as the 3D but its a 14 day kit. Its a bit different from professional because the professional has a longer and wider strip. They are both made from new non slip technology that is much stronger and it takes a lot to strip them off your teeth.
Recap: Supreme is strongest and lasts 21 days it is non slip.
The other two are same strength but the 3D has 20 days supply and Advance is 14 days. All 3 are aimed with really heavy discoloraton.
Thank you crestwhitestripsuk for this awesome review