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Thank you for your message.

I have purchase my white-strips from Mannings, our largest pharmacy chain. I have sent you a message earlier to confirm Mannings is an authorized Crest Whitestrips seller. The receipts of mannings were uploaded on ebay for further regular verification.

I personally contacted Crest USA for use instructions. After providing the product code on pouch of white-strips, they could locate the product specifications and told me that the strips were safe to use. Additionally, the white-strips has been using advance seal technology. The texture of white-strips were dryer than previous versions. In the past Crest sold Advanced Seal White-stips and professional effect white-strips as two separate items. The current professional effects carried the advance seal technology.

Please let me know if you need further information or assistance.