Features: The Paradome DG466 differentiates between incoming and outgoing movements, which is ideal for protecting open balconies and patio doors. Two dual element sensors (determine if movement is incoming or outgoing) One incoming detection relay output One outgoing detection relay output Adjustable return delay timer (exit and reenter without causing an alarm) Patented Digital Detection 67cm (2.2ft) X 4.8m (16ft) and 60cm (2ft) X 4.8m (16ft)