SR-740 PG2 is a two-way wireless outdoor siren (IP55). It provides the perfect security solution for home owners with a PowerMaster wireless intrusion alarm system who are looking for an affordable and easy to install outdoor siren. It excels in offering cabling-free installation and optional extended time between battery changes.SR-740 PG2 uses Visonic's ground-breaking PowerG technology, which combines several field-proven, advanced technologies and the highly reliable AES encryption method. The combination of technologies delivers an extended transmission range, far greater than the industry standard - enabling a very large distance between the siren and the control panel. It also provides an extended battery life that makes it easy and affordable to maintain.The siren's two-way, fully supervised communication with the control panel provides visual and audial notifications of intrusions, fire alarms, low battery and communication disruptions.