Plastic pen ,LED pen ,light up pen,UV light pen Material :plastic One LED Control by button IR pen Material:plastic LED : one specifically the Vishay TSAL6400 LED ... pen disign ,the IR light stays on when the button is pressed down one the tip of the IR pen ,an IR led with ... mousepointer ,when the user press the button on the pen ,the LED light isturned on .even though human eyes can not see ...