4WG means 4-pass Wet-back fire tube Boiler with Gun Burner in
Commercial
Similar to 4WG
4WW - Four-Wheel Wagon
4WW - Water Wiggler Water Agitator, model 4
4WW - Four-Wheeled Walker
95 - version 4.0 of Microsoft Windows
98 - version 4.1 of Microsoft Windows
A/C - Air Conditioning
AA - Adjustable Arms
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