Turning Technologies Response Card RF Clicker Lightweight, compact, grey "credit card" format. Answer Key - answer transmitted automatically. Deep sleep mode when not in use. Durable, rugged case ensures maximum longevity under extreme condition * 200 foot range (400 ft coverage) - Select a channel in less than five seconds, indicating session choice - Select a channel anytime - even when a session is underway Average battery life is 6 to 12 months (takes 2 CR2032 coin batteries)