No external power source required, plugs straight into any USB port and powered directly by any USB port. Use the keyboard attachment rubber to vacuum the dust and other particals trapped underneath the keyboard keys, by sliding te squeezable tube between keys. Two vacuum cleaning attachments includes one bristle attachment and one flesxible rubber, computer keyboard tool attachment. Use the brush abd suction tube attachment for general cleaning of air vents, monitor and computer areas,... * Free Worldwide Shipping with registred airmail service - Livraison gratuite dans le monde entier, envoi enregistre par avion - Freies weltweites Verschiffen mit registred Luftpostverkehr - Trasporto in tutto il mondo libero con il servizio di airmail registred - Envio mundial libre con servicio de correo aereo registred. * Thank you for visiting eTreasures.