Writing has never been more fun than with our Aqua Bubble Pen. Children cant wait to write with these incredible pens. Heat from your fingers causes the colored liquid inside the pens chamber to boil, creating oodles of bubbles and fun. Safari Ltd takes pride in providing breathtaking, innovative and value priced scientific instruments. Featured is our Safari Science Aqua Bubble Pen Size: 2 W x 6 H (5 x 15 cm). Choice of color: Blue, Red, Purple or Green. Note - NOT A TOY! Boiler chamber is made of glass. Suggested age 7+ UPC CODE: 95866649302