Why is this unbranded but stamped Phillips SOnicare?

Thanks for clarifying your question. The Philips Sonicare Protective Clean 5100 for R2899 is a great option as it is the most similar model to the 4300 you originally wanted. As one of Philips' premium sonic toothbrush lines, you can be assured of the quality, reliability and cleaning performance the Protective Clean is known for. It comes with 2 brush heads and a 2-year warranty for protection. Let me know if you have any other questions!