Aprilaire Model 500 Automatic Whole-house Bypass Humidifier with Digital Control. Includes water panel, outdoor temp sensor, saddle valve, 24v transformer, built in damper. Unit is 15.62″ wide x 13″tall and 10.25″ deep. Plenum opening size 9.5″ SQ Bypass connection comes mounted on the left and can be modified for the right side …