... 4G wireless presenter 2.USB laser pointer,page up and down,blank screen 3.Red laser presenter with CE &RoHS Features Easy ... black screen/full screen,*Esc2.4GHz Wireless Connection Presentation remote USB receiverWavelength:630-670nmuses 1pc 3A batteriesDimensions:105*40*27mmIt ... For teching ,Meeting,Speech,Training etc. 2.4G wireless presenter ,USB laser pointer ,Red laser presenter with CE &RoHS