Pen that works with 2 AAA batteries, for use with all the Hot Dots set we have in our store! Hot Dots Pen and cards provide self-checking learning in a variety of subjects: Early Years Skills, Maths, Literacy and Science. Talking Pen provides instant feedback, Gently indicating incorrect answers and congratulating correct ones. Sounds can be muted for quiet classroom use. Interactive pen requires 2 AAA batteries, not included