Pull the pin and lob it at your intended victims. After a 20 second delay, your Sonic Grenade will sound its annoying alarm continuously until you replace the pin. Very annoying. Probably the most annoying device in the world - wake recalcitrant teenagers, annoy parents or teachers, interrupt meetings etc. Three annoying pitch levels. Requires 3 x AAA batteries (not included). Did we mention it`s annoying? Specifications Size: 125 mm high Battteries: 3 x AAA (not included)