Standard Horizon VLH3000A 30W Dual Zone PA/Loud Hailer (Black)Adjustable Backlight The VLH 3000A has an adjustable backlight feature to dim the lighting on the display and buttons for better night time use. Two 30 Watt PA Outputs, One Forward One Aft With two 30 watt PA outputs, you are able to connect one PA forward and one aft, or transmit out of both simultaneously. Four foghorn signals can be used for a variety of weather conditions and there is also the bells, whistles, horn or siren. Two Intercom