Economy version: 109dB(A) @ 1m, IP44 sealed electronics, adjustable lid and wall tamper detection. 109dB Volume IP44 Environmental Protection Patented Safety Engineer Hold-off Mode Advanced Microprocessor Technology Lid and Wall Tamper Polycarbonate Construction Selectable SAB/SCB Mode Strobe Tube Saver Twin Alternating LEDs PD6662:2017 Grade 2 Class IV