Brush head is not replaceable. Batteries are replaceable. AAA batteries included. Use only AAA Alkaline batteries; see manufacturer's usage instructions for safe handling and usage. Do not mix old and new batteries. Do not mix alkaline standard (carbon-zinc) with rechargeable (nickel-cadmium) batteries. Operating Instructions:
1. Side switch up to turn on brush.
2. Gently glide bristles back and forth against the teeth/gum surfaces without pressing hard for about 2 minutes while brushing your teeth.