Hp ,cp,none peroxide.
-Hp means hydrogen peroxide ,H2O2,it range from 0.1%-35%,you can order 1%,6%.7%,10%,16%,25% etc.if hp gel over 16%hp,the gum protection gel must be used. -Cp means carbamide peroxide,it range from 0.1%-44%,you can order any percentage.if the cp gel over 35%,gum protection gel must be used. None peroxide gel.