China Etchant Recommended etching time 30 - 60 seconds for enamel. 鈥?A semi-gel type for easy application and adhesion 鈥?Thickener is Food-grade materials 鈥?Leave no residues on the surface of etched tooth like silica thickened etchants 鈥?Blue color provide highly visible contrast Gel stays where placed without overflowing Ideal medium viscosity DescriptionContainITEM NO. Ecthant Acid Gel2.5ml/pcs0901-30 5.0ml/pcs0901-31 10ml/pcs0901-32 DENRUM EXTRATM Orthodontic Etchant - is an etch gel containing 37 % Phosphoric Acid thickened with natural polymeric materials 鈼?Recommended etching time 30 鈥?60 seconds for enamel. 鈼?A semi-gel type for easy application and adhesion 鈼?Thickener is Food-grade materials 鈼?Leave no residues on the surface of etched tooth like silica thickened etchants Blue color provide highly visible contrast Gel stays where placed without overflowing Ideal medium viscosity 鈼?1x5ml syringe,2 application tips, 1 sealed cap.China Etchant website:http://www.denrum.com.cn/orthodontic-adhesive/etchant/