Durable, portable, extendable, retractable. Replaceable felt contact head. Comfortable sponge handle, sturdy when fully opened, not shaky. Suitable for traditional blackboard, electric whiteboard, it will not damage the screen. Description This strong robust model provides extra impact. It is ideal for educational or training course instruction. It allows the user to be further to the side of a presentation. It can present information to reinforce students' knowledge in the subject. Features Size: tube diameter 6mm-12mm. Stretched length of about 1000mm, shrinkage of about 210mm, felt head diameter 8mm, sponge handle diameter 25mm. Weight: 62g Color include: black, blue, red, orange Package includes: 1pc* whip pen