Formed as the `SL’-series, Siemens is offering a latest version to its high-fidelity speakers and speaker-strobes of notification appliances. The Siemens `SL’-series offers an additional range of low and high Candela settings that makes these sophisticated notification appliances ideal for new installs and retrofit applications. With a vast frequency-response range (300 to 8000 Hertz), the SLSPW series and SLSPSW feature leading intelligibility with crisp, clear voice messages and tone signaling, ideal for emergency communications, mass notification, voice evacuation and fire alarm. The speaker portion of these appliances meets regulatory standards, per UL 464 (for 520 Hz.), in order to comply with National Fire Protection Association requirements relative to 520 Hertz tone for Sleeping Areas.