Power Sonic PS series of sealed lead acid batteries have been designed with AGM (Absorbent Glass Mat) technology to ensure superior performance and reliability. The PS series has been specifically engineered for use in general purpose float and light cyclic applications including fire and security systems, emergency lighting, UPS, toys and medical devices. The PS HD series are Heavy-duty rechargeable lead acid batteries with increased vibration resistant design for all your pitch control, braking, and renewable energy applications. A number of our PS range of batteries are VdS approved. VdS is 1 of the world's leading inspection and certification companies in the fire protection and security industry. They set international standards with the publication of a comprehensive set of rules and guidelines for fire protection and safety equipment. VdS is 1 of the only testing institutes certifying sealed lead acid batteries, our VdS approved batteries are indispensable for the reliability of many security and fire systems. The VdS quality seal certifies that our batteries are of optimum quality for use in fire, security, and life safety applications.