Carex is a fluoride containing varnish with the following characteristics except-

Carex  is another  fluoride varnish and contains a lower fluoride concentration than Duraphat (1.8% fluoride) and has efficacy equivalent to that of Duraphat as a caries -preventive agent.  Technique of varnish application : After prophylaxis, teeth are dried, but not isolated with cotton rolls since varnish sticks to cotton.  A  total of 0.3 - 0.5  ml of varnish equivalent to 6.9-11.5 mg F is required to cover the full dentition.  Application is done first on the lower arch and then on the upper arch, using a single tufted  small brush, starting  with the proximal surfaces.  After application, the patient is made to sit with the mouth open for 4 minutes before spitting to let Duraphat set on teeth which is  further  enhanced  by  saliva. (FIuorprotector sets faster than Duraphat).  Patient is asked not to rinse or drink anything at all for one hour and not to eat anything  solid  but take  liquids  and semisolids only till the next morning, so that contact between varnish and tooth surfaces for about 18 hours is maintained for  prolonged  interaction  between fluoride and enamel.