PLEASE SEE PICTURE BEFORE BUYING THIS UNIT. E50SB-W: SURFACE BACK BOX, WHITE, FOR E50 SPEAKER ADA/NFPA/ANSI compliant Complies with OSHA 29 Part 1910.165 Wall mount speaker strobe models with field selectable candela settings of 15/30/75/110cd. Or 135/185cd (Multi-Candela models), or 1575cd (Single Candela model) Field selectable taps for 25 or 70 VRMS operation from 1/8 watt up to 2 watts High-efficiency design for maximum output at minimum wattage across a frequency range of 400 to 4000 HZ 24 VDC strobes produce 1 flash per second. The wide UL ?Regulated Voltage? of 16 to 33 volts using filtered DC or unfiltered VRMS input voltage Synchronize with Wheelock SM, DSM or Wheelock PS-12/24-8CP and PS-12/24-8MP Power Supply with built-in sync protocol Mount to 4? square x 2-1/8? deep backbox with no extension ring required Snap-on grille cover with no visible mounting screws Fast installation with IN/OUT screw terminals using #12 to #18 AWG wires Cooper Wheelock E50SB-W Backbox ADA/NFPA/ANSI compliant Complies with OSHA 29 Part 1910.165 Wall mount speaker strobe models with field selectable candela settings of 15/30/75/110cd. Or 135/185cd (Multi-Candela models), or 1575cd (Single Candela model) Field selectable taps for 25 or 70 VRMS operation from 1/8 watt up to 2 watts High-efficiency design for maximum output at minimum wattage across a frequency range of 400 to 4000 HZ 24 VDC strobes produce 1 flash per second. The wide UL ?Regulated Voltage? of 16 to 33 volts using filtered DC or unfiltered VRMS input voltage Synchronize with Wheelock SM, DSM or Wheelock PS-12/24-8CP and PS-12/24-8MP Power Supply with built-in sync protocol Mount to 4? square x 2-1/8? deep backbox with no extension ring required Snap-on grille cover with no visible mounting screws 20% RESTOCKING FEES AND SHIPPING WILL BE CHARGED. IF ITEM IS FUNTIONAL OR INCOMPLETE. An Important Message Regarding USPS Tracking Numbers Due to high volume of shipments sent through USPS, Tracking numbers get recycled on occasion. This means, when you receive the notificaiton that your package has been shipped via USPS, and you try to track the status of the package, it may show your package was Delivered even though the label was just generated. Please don't panic, the solution to this issue is to wait until the Post Office scans the label, then the tracking information will update accordingly. Please let us know if you have any questions. Your feedback is extremely important to us! If you are satisfied with our service please take the time to give us positive feedback. We tremendously appreciate it! We strive for your complete satisfaction. Likewise, if you have any issues, please contact us first, and we promise we will do our best to satisfy your needs and solve the problem. If we resolve your problem, we kindly ask you to still leave us positive feedback. Your kindness will be extremely appreciated!