This Loud Wireless Doorbell Kit Is Designed To Be Heard In Residential & Commercial Applications Long range wireless signal strength penetrates steel, reinforced concrete, metal, block, brick, stone, stucco, glass, wood, etc Transmits a blanketing 360 degree signal able to traverse multiple floors & walls, through unattached buildings & structures - even large industrial buildings & residential condominiums Up to 3/4 mile range specifically designed for large, noisy & busy applications such as warehouses, fulfillment centers, manufacturing production facilities or any residential applicationIndustrial grade 120db 12VDC 6" bell immediately covers the area with a loud ringing bell sound when transmitter is activated Multi Purpose Industrial Grade Wireless Waterproof Transmitter & Plug In Receiver Offers Uncomplicated & Quick Installation Even In The Most Demanding Environments Operates just like a standard doorbell push button when someone presses push button at a closed or locked gate, office entry, dock door, warehouse door, work station, etc.Can also operate as a magnetic door chime - alerts you every time someone opens an unlocked door, gate, secure area, window, etc, when the included contact sensor separates from the transmitterHeavy duty IP55 waterproof rated transmitter is constructed of shatter resistant ABS that stands up to demanding commercial conditions and can be painted to the color of your choiceReceiver has an extra large high quality 2 1/2" speaker producing crisp,distortion free sound. Select one of 12 pleasant tunes. Volume is easily adjustable from mute to 95db. Bell is a constant 120db. This Doorbell Kit Is Expandable & Configurable To Suit Your Needs Allowing For Complete & Comprehensive Coverage With Built In Options No Other System Offers Able to pair an unlimited number of transmitters to receivers. You can utilize as many receivers as neededEach receiver is uniquely equipped with four 12VDC outputs allowing you to connect a wide variety of 12VDC accessories such as strobe lights, sirens, buzzers & bells, etcEven more advanced features for the engineers & technically inclined - The transmitter features (1) N/O, N/C relay & plug in receiver has (1) “C” relay 3/4 Mile Range Long Range Wireless Doorbell Powerful & Expandable As Well As Easy To Install For Comprehensive Coverage Perfect Doorbell System For Large Facilities IP55 Waterproof Transmitter Reliable Waterproof Extra Long Range Transmitter Works On Multiple Door Types Penetrating Even the Toughest Objects Expandable For Comptehensive Coverage Hear The Doorbell Even In The Loudest Warehouses, Manufacturing Facilities, Assembly Lines & Over Heavy Equipment Multi Purpose Transmitter - Push Button & Door Contact Multi Purpose Transmitter Can Also Be Used As A Magnetic Door Contact Where Chime Sounds When Door Opens Residential Doorbell For Large Homes & Hearing Impaired Hearing Impaired Doorbell Hearing Impaired Or Hard Of Hearing? This Doorbell Kit Can Be Heard Throughout Your Home - Usually Without Additional Receivers Long Range Doorbell Have A Large, Multi Level Home or Home With A Barn, Shed, Gate House or Pool House? This Wireless Doorbell Transmitter Has 3/4 Mile Range Caregiver Door Alarm Notification Excellent For Use As A Door Alarm To Instantly Alert Caregivers When Children, Elderly, Dementia Patients, Etc Leave Their Rooms Multi Functional Long Range Wireless Loud Doorbell Designed In The USA & Made With Precision In China Industry Leading Innovation Long Range - Up To 3/4 MileExtra Loud - Up To 120dbExpandable - Add An Unlimited Number Of Transmitters & Receivers.Compatible - Connect Other 12 Volt DevicesCommercial Grade - IP55 Rated Transmitter & Shatter Resistant ABS ERA-LOUD-DOORBELL Specifications Range: Up to 4000ftSounds: 12 TunesVolume: Adjustable Knob Control (0db - 95db)Receiver Power: Plug In Class 2 UL LISTED AC Transformer (120v 60Hz 18Watts)Receiver Outputs: (4) 12VDC, (1) N/O, N/C RelayTransmitter Power: 1 x 3V CR2 Long Life Batter+yTransmitter Outputs: (1) "C" RelayBell: 6" 12VDC 120db Package Includes 1 x Push Button Transmitter1 x Door/Window Contact Sensor1 x Plugin Chime Receiver1 x 12VDC 6" Loud Ringing Bell1 x 15′ 18AWG Low-Voltage Double-Strand Wire4 x Screws1 x 3V CR2 battery1 x User Manual