According to our information, this should fit. :)

The C3 brush head is not specifically designed for the Philips Sonicare Series 5300. The 5300 series usually uses the W2 Optimal White brush head. However, many Sonicare brush heads are compatible with most rechargeable Sonicare toothbrushes due to their standard size. To ensure that the C3 brush head will work with your 5300 series, I recommend consulting the official Philips Sonicare website or contacting Philips directly.